Plasma processing apparatus and etching method

ABSTRACT

A plasma processing apparatus comprising: a chamber; a substrate support disposed in the chamber and including a lower electrode, a substrate supporting surface for supporting a substrate, and an edge ring disposed to surround the substrate placed on the substrate supporting surface; an upper electrode disposed above the lower electrode; a power supply portion configured to supply two or more powers having different frequencies, the power supply portion including a source power supply configured to supply a source power for generating plasma from a gas in the chamber to the upper electrode or the lower electrode, and at least one bias power supply configured to supply one bias power or two or more bias powers having different frequencies to the lower electrode; at least one variable passive component electrically connected to the edge ring; and at least one bypass circuit that electrically connects the power supply portion and the edge ring and is configured to supply a part of at least one power selected from the group consisting of the source power and at least one bias power to the edge ring.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application Nos.2021-153295 filed on Sep. 21, 2021 and 2022-141352 filed on Sep. 6,2022, the entire contents of each are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a plasma processing apparatus and anetching method.

BACKGROUND

Japanese Laid-open Patent Publication No. 2017-228526 discloses a systemfor controlling directionality of an ion bundle in an edge region in aplasma chamber. The system includes an RF generator configured togenerate an RF signal, an impedance matching circuit receiving the RFsignal to generate a corrected RF signal, and a plasma chamber. Theplasma chamber includes an edge ring and a coupling ring for receiving acorrected RF signal. The coupling ring includes an electrode receivingthe corrected RF signal and an electrode generating capacitance betweenthe coupling ring and the edge ring and controlling the directionalityof the ion bundle.

SUMMARY

The technique according to the present disclosure appropriately controlsan incident angle of ions in a plasma with respect to an edge region ofa substrate in plasma processing.

One aspect of the present disclosure is a plasma processing apparatuscomprising, a chamber, a substrate support disposed in the chamber andincluding a lower electrode, a substrate supporting surface forsupporting a substrate, and an edge ring disposed to surround thesubstrate placed on the substrate supporting surface, an upper electrodedisposed above the lower electrode; a power supply configured to supplytwo or more powers having different frequencies, the power supplyincluding a source power supply configured to supply a source power forgenerating plasma from a gas in the chamber to the upper electrode orthe lower electrode, and at least one bias power supply configured tosupply one bias power or two or more bias powers having differentfrequencies to the lower electrode, at least one variable passivecomponent electrically connected to the edge ring and at least onebypass circuit that electrically connects the power supply and the edgering and is configured to supply a part of at least one power selectedfrom the group consisting of the source power and at least one biaspower to the edge ring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view schematically illustrating aconfiguration of an etching apparatus according to the presentembodiment.

FIG. 2A is a longitudinal sectional view schematically illustrating aconfiguration of the periphery of an edge ring according to the presentembodiment.

FIG. 2B is a longitudinal sectional view schematically illustrating aconfiguration of the periphery of an edge ring according to the presentembodiment.

FIG. 3A is a view illustrating a change in a shape of a sheath due toconsumption of an edge ring and an occurrence of inclination in adirection of incidence of ions.

FIG. 3B is a view illustrating a change in a shape of a sheath due toconsumption of an edge ring and an occurrence of inclination in adirection of incidence of ions.

FIG. 4A is an explanatory view illustrating a change in a shape of asheath and an occurrence of inclination in a direction of incidence ofions.

FIG. 4B is an explanatory view illustrating a change in a shape of asheath and an occurrence of inclination in a direction of incidence ofions.

FIG. 5 is an explanatory view illustrating a form in which a tilt angleis changed when an initial tilt angle is not adjusted.

FIG. 6 is an explanatory view illustrating a form in which a tilt angleis changed when an initial tilt angle is adjusted.

FIGS. 7A and 7B are explanatory views illustrating a control range of atilt angle by a tilt control knob.

FIG. 8A is explanatory view illustrating an example of an arrangement ofa bypass circuit.

FIG. 8B is an explanatory view illustrating an example of an arrangementof a bypass circuit.

FIG. 9A is an explanatory view illustrating a configuration example ofan arrangement of a bypass circuit.

FIG. 9B is an explanatory view illustrating a configuration example ofan arrangement of a bypass circuit.

FIG. 9C is an explanatory view illustrating a configuration example ofan arrangement of a bypass circuit.

FIG. 9D is an explanatory view illustrating a configuration example ofan arrangement of a bypass circuit.

FIG. 9E is an explanatory view illustrating a configuration example ofan arrangement of a bypass circuit.

FIG. 9F is an explanatory view illustrating a configuration example ofthe arrangement of a bypass circuit.

FIG. 10 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 11 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 12 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 13 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 14 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 15 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 16 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 17 is an explanatory view illustrating an example of a controlmethod of a tilt angle.

FIG. 18 is an explanatory view illustrating an example of aconfiguration of a bypass circuit and a tilt control knob.

FIG. 19 is an explanatory view illustrating an example of aconfiguration of a bypass circuit and a tilt control knob.

FIG. 20 is an explanatory view illustrating an example of aconfiguration of a bypass circuit and a tilt control knob.

FIG. 21A is an explanatory view illustrating an example of aconfiguration of a bypass circuit and a tilt control knob.

FIG. 21B is an explanatory view illustrating an example of aconfiguration of a bypass circuit and a tilt control knob.

FIG. 22 is a longitudinal sectional view schematically illustrating aconfiguration around an edge ring according to another embodiment.

FIG. 23A is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 23B is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 23C is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 23D is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 23E is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 23F is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24A is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24B is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24C is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24D is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24E is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24F is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 24G is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion.

FIG. 25A is a plan view illustrating an example of a configuration of aconnecting portion.

FIG. 25B is a plan view illustrating an example of a configuration of aconnecting portion.

FIG. 25C is a plan view illustrating an example of a configuration of aconnecting portion.

FIG. 26A is an explanatory view schematically illustrating an example ofa configuration of a connecting portion and an RF filter.

FIG. 26B is an explanatory view schematically illustrating an example ofa configuration of a connecting portion and an RF filter.

FIG. 26C is an explanatory view schematically illustrating an example ofa configuration of a connecting portion and an RF filter.

FIG. 27A is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 27B is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 27C is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 27D is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 28A is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 28B is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 28C is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

FIG. 28D is a longitudinal sectional view illustrating an example of aconfiguration of a connecting portion and a lifting device.

DETAILED DESCRIPTION

In a semiconductor device manufacturing process, a plasma processing,such as etching, is performed on a semiconductor wafer (hereinafterreferred to as “wafer”). In the plasma processing, plasma is generatedby exciting a processing gas, and the wafer is processed by the plasma.

The plasma processing is performed in a plasma processing apparatus. Aplasma processing apparatus generally includes a chamber, a stage, and aradio frequency (RF) power supply. In an example, the high frequencypower supply includes a first high frequency power supply and a secondhigh frequency power supply. The first high frequency power supplysupplies first high frequency power to generate plasma of a gas in thechamber. The second high frequency power supply supplies second highfrequency power for bias to a lower electrode in order to attract ionsinto the wafer. The stage is provided in the chamber. The stage has alower electrode and an electrostatic chuck. In an example, an edge ringis disposed on an electrostatic chuck to surround the wafer mounted onthe electrostatic chuck. The edge ring is provided to improve theuniformity of the plasma processing to the wafer.

The edge ring is consumed over time during which the plasma processingis performed, so that a thickness of the edge ring decreases. As thethickness of the edge ring decreases, a shape of a sheath changes abovethe edge region of the wafer and the edge region. When the shape of thesheath is changed in this way, an incident direction of ions in the edgeregion of the wafer is inclined with respect to a vertical direction. Asa result, a concave portion formed in the edge region of the wafer isinclined with respect to a thickness direction of the wafer.

In order to form the concave portion extending in the thicknessdirection of the wafer in the edge region of the wafer, that is, tocontrol a tilt angle that is an inclination with respect to thethickness direction of the wafer W of the concave portion, aninclination of the incident direction of ions to the edge region of thewafer needs to be adjusted. Therefore, in order to control the incidentdirection (directionality of the ion bundle) of ions to the edge region,for example, in Japanese Laid-open Patent Publication No. 2017-228526,it is proposed to generate capacitance between the electrode of thecoupling ring and the edge ring as described above.

Here, when the tilt angle is controlled for each of high frequencypowers of a plurality of frequencies, an initial tilt angle before aplasma processing (hereinafter referred to as “initial tilt angle”) maybe different for each frequency. The initial tilt angle is, for example,a tilt angle when an etching apparatus 1 is operated or when the etchingapparatus 1 is operated after maintenance, and once the initial tiltangle is adjusted, there is no need to adjust the tilt angle again. Inthis way, when the initial tilt angle is not uniform, for example, itmay be sometimes difficult to align and control the tilt angle for eachfrequency even if the capacitance is generated and an incidence angle isadjusted, as disclosed in Japanese Laid-open Patent Publication No.2017-228526.

The technique according to the present disclosure appropriately controla tilt angle in an edge region by adjusting an initial tilt angle in anedge region of a substrate in etching.

Hereinafter, an etching apparatus as a plasma processing apparatus andetching method according to the present embodiment are described withreference to the drawings. In addition, in this specification anddrawing, elements which have substantially the same functionalconfiguration are given the same reference numerals and redundantdescriptions thereof are omitted.

<Etching Apparatus>

First, an etching apparatus according to the present embodiment isdescribed. FIG. 1 is a longitudinal sectional view schematicallyillustrating a configuration of an etching apparatus 1. FIGS. 2A and 2Bare each a longitudinal sectional view schematically illustrating aconfiguration around an edge ring. The etching apparatus 1 is acapacitively coupled etching apparatus. The etching apparatus 1 performsetching on the wafer W as a substrate.

As illustrated in FIG. 1 , the etching apparatus 1 has a substantiallycylindrical chamber 10. The chamber 10 defines a processing space S inwhich plasma is generated. The chamber 10 is formed of, for example,aluminum. The chamber 10 is connected to a ground potential.

A stage 11 as a substrate support on which the wafer W is mounted isaccommodated in the chamber 10. The stage 11 has a lower electrode 12,an electrostatic chuck 13, and an edge ring 14. In addition, anelectrode plate (not shown) formed of, for example, aluminum may beprovided on a lower surface side of the lower electrode 12.

The lower electrode 12 is formed of a conductive material, for example,a metal, such as aluminum, and has a substantially disk shape.

Further, the stage 11 may include a temperature control moduleconfigured to control at least one of the electrostatic chuck 13, theedge ring 14, and the wafer W to have a desired temperature. Thetemperature control module may include a heater, a flow path, or acombination thereof. A temperature control medium, such as a refrigerantor a heat transfer gas, flows through the flow path.

In an example, a flow path 15 a is formed inside the lower electrode 12.A temperature control medium is supplied to the flow path 15 a from achiller unit (not shown) provided outside the chamber 10 through aninlet pipe 15 b. The temperature control medium supplied to the flowpath 15 a is returned to the chiller unit via an outlet flow path 15 c.By circulating a temperature control medium, for example, a coolant,such as cooling water, in the flow passage 15 a, the electrostatic chuck13, the edge ring 14, and the wafer W may be cooled to have a desiredtemperature.

The electrostatic chuck 13 is provided on the lower electrode 12. In anexample, the electrostatic chuck 13 is a member configured to be able toadsorb and hold both the wafer W and the edge ring 14 by electrostaticforce. The electrostatic chuck 13 is formed such that an upper surfaceat a central portion thereof is higher than an upper surface at aperipheral portion thereof. The upper surface at the central portion ofthe electrostatic chuck 13 is a wafer supporting surface as a substratesupporting surface for supporting the wafer W, and in an example, theupper surface at the peripheral portion of the electrostatic chuck 13 isan edge ring supporting surface for supporting the edge ring 14. Inaddition, the lower electrode 12 may be provided inside theelectrostatic chuck 13.

In an example, a first electrode 16 a for adsorbing and holding thewafer W is provided in the central portion of the electrostatic chuck13. Inside the electrostatic chuck 13, a second electrode 16 b foradsorbing and holding the edge ring 14 is provided at a peripheralportion thereof. The electrostatic chuck 13 has a configuration in whichelectrodes 16 a and 16 b are interposed between insulating materialsformed of an insulating material.

A DC voltage from a DC power supply (not shown) is applied to the firstelectrode 16 a. The wafer W is adsorbed and held on the upper surface ofthe central portion of the electrostatic chuck 13 by electrostatic forcegenerated thereby. Similarly, a DC voltage from a DC power supply (notshown) is applied to the second electrode 16 b. In an example, the edgering 14 is adsorbed and held on the upper surface of the peripheryportion of the electrostatic chuck 13 by electrostatic force generatedthereby.

Further, in the present embodiment, the central portion of theelectrostatic chuck 13 provided with the first electrode 16 a and theperipheral portion provided with the second electrode 16 b areintegrated with each other, but these central portions and theperipheral portions may be separately provided. In addition, both of thefirst electrode 16 a and the second electrode 16 b may be unipolarelectrodes or bipolar electrodes.

In addition, in the present embodiment, the edge ring 14 iselectrostatically adsorbed to the electrostatic chuck 13 by applying aDC voltage to the second electrode 16 b, but a method of holding theedge ring 14 is limited thereto. For example, the edge ring 14 may beheld adsorbed and held using an adsorption sheet, or the edge ring 14may be clamped to be adsorbed and held. Alternatively, the edge ring 14may be held by the weight of the edge ring 14.

The edge ring 14 is an annular member disposed to surround the wafer Wmounted on the upper surface of the central portion of the electrostaticchuck 13. The edge ring 14 is provided to improve uniformity of etching.For this reason, the edge ring may be formed of a material appropriatelyselected according to etching, may have conductivity, and may be formedof, for example, Si or SiC.

The stage 11 configured as described above is fastened to asubstantially cylindrical support member 17 provided at the bottom ofthe chamber 10. The supporting member 17 is formed of, for example, aninsulator, such as ceramic or quartz.

A shower head 20 is provided above the stage 11 to face the stage 11.The shower head 20 includes an electrode plate 21 disposed to face theprocessing space S and an electrode support body 22 provided above theelectrode plate 21. The electrode plate 21 functions as a pair of upperelectrodes with the lower electrode 12. As is described below, when afirst high frequency power supply 50 is electrically coupled to thelower electrode 12, the shower head 20 is connected to a groundpotential. Further, the shower head 20 is supported on an upper portion(ceiling surface) of the chamber 10 via an insulating shielding member23.

The electrode plate 21 is provided with a plurality of gas outlets 21 afor supplying a processing gas transferred from a gas diffusion chamber22 a to be described below to the processing space S. The electrodeplate 21 is formed of, for example, a conductor or semiconductor havinga low electrical resistivity with little Joule heat being generated.

The electrode support body 22 detachably supports the electrode plate21. The electrode support body 22 has a configuration in which a filmhaving plasma resistance is formed on a surface of a conductivematerial, such as aluminum, for example. This film may be a film formedby anodizing or a film formed of ceramics, such as yttrium oxide. A gasdiffusion chamber 22 a is formed inside the electrode support body 22. Aplurality of gas distribution holes 22 b communicating with a gas outlet21 a are formed from the gas diffusion chamber 22 a. In addition, thegas diffusion chamber 22 a is provided with a gas introduction hole 22 cconnected to a gas supply pipe 33, which is described below.

Further, a gas source group 30 for supplying a processing gas to the gasdiffusion chamber 22 a is connected to the electrode support body 22through a flow control device group 31, a valve group 32, a gas supplypipe 33, the gas introduction hole 22 c.

The gas source group 30 has a plurality of types of gas sourcesnecessary for etching. The flow control device group 31 includes aplurality of flow controllers, and the valve group 32 includes aplurality of valves. Each of the plurality of flow controllers in theflow control device group 31 is a mass flow controller or a pressurecontrol type flow controller. In the etching apparatus 1, a processinggas from one or more gas sources selected from the gas source group 30is supplied to gas diffusion chamber 22 a through the flow controldevice group 31, the valve group 32, the gas supply pipe 33, and the gasintroduction hole 22 c. Then, the processing gas supplied to the gasdiffusion chamber 22 a may be dispersed and supplied in a shower shapeinto the processing space S through the gas distribution hole 22 b andthe gas outlet 21 a.

At the bottom of the chamber 10, a baffle plate 40 is provided betweenan inner wall of the chamber 10 and the support member 17. The baffleplate 40 is constituted by, for example, coating an aluminum materialwith ceramics, such as yttrium oxide. A plurality of through holes areformed in the baffle plate 40. The processing space S communicates withan exhaust port 41 via the baffle plate 40. An exhaust device 42, suchas a vacuum pump, is connected to the exhaust port 41, and pressureinside the processing space S may be reduced by the exhaust device.

In addition, a carry-in/out port 43 for the wafer W is formed on asidewall of the chamber 10, and the carry-in/out port 43 may be openedand closed by a gate valve 44.

As illustrated in FIGS. 1, 2A, and 2B, the etching apparatus 1 furtherincludes a first high frequency power supply 50 as a source powersupply, a second high frequency power supply 51 as a bias power supply,a third high frequency power supply 52 as a bias power supply, and amatching device 53. The first high frequency power supply 50, the secondhigh frequency power supply 51, and the third high frequency powersupply 52 are coupled to the lower electrode 12 through a first matchingcircuit 54, a second matching circuit 55, and a third matching circuit56, respectively. Although the first matching circuit 54, the secondmatching circuit 55, and the third matching circuit 56 are providedinside one matching device 53 in this embodiment, their arrangement isnot limited. For example, they may be provided inside separate matchingdevices or may be provided outside the matching device. Also, the firsthigh frequency power supply 50, the second high frequency power supply51, and the third high frequency power supply 52 constitute a powersupply in the present disclosure. The first high frequency power supply50 generates first high frequency power HF, which is source RF power(source power) for plasma generation, and supplies the first highfrequency power HF to the lower electrode 12. The first high frequencypower HF may be a first frequency within the range of 27 MHz to 100 MHz,and in an example, it is 40 MHz. The first high frequency power supply50 is coupled to the lower electrode 12 through the first matchingcircuit 54 of the matching device 53. The first matching circuit 54 is acircuit for matching output impedance of the first high frequency powersupply 50 with input impedance of a load side (lower electrode 12 side).In addition, the first high frequency power supply 50 may not beelectrically coupled to the lower electrode 12, or may be coupled to theshower head 20, that is, an upper electrode, via the first matchingcircuit 54. Alternatively, instead of the first high frequency powersupply 50, a pulsed power supply configured to apply a pulse voltageother than high frequency power to the lower electrode 12 may also beused. This pulsed power supply is similar to a pulsed power supply usedinstead of the second high frequency power supply 51 and the third highfrequency power supply 52 described below.

The second high frequency power supply 51 generates second highfrequency power LF1, which is bias RF power (bias power) for attractingions into the wafer W, and supplies the second high frequency power LF1to the lower electrode 12. The second high frequency power LF1 may be asecond frequency within the range of 100 kHz to 15 MHz, and in anexample, it is 400 kHz. The second high frequency power supply 51 iscoupled to the lower electrode 12 through the second matching circuit 55of the matching device 53. The second matching circuit 55 is a circuitfor matching output impedance of the second high frequency power supply51 with input impedance of the load side (lower electrode 12 side).

The third high frequency power supply 52 generates a third highfrequency power LF2, which is bias RF power (bias power) for attractingions into the wafer W, and supplies the third high frequency power LF2to the lower electrode 12. The third high frequency power LF2 may be athird frequency within the range of 100 kHz to 15 MHz, may be differentfrom the second frequency, and is 13 MHz in an example. The third highfrequency power supply 52 is coupled to the lower electrode 12 via thethird matching circuit 56 of the matching device 53. The third matchingcircuit 56 is a circuit for matching output impedance of the third highfrequency power supply 52 with input impedance of the load side (lowerelectrode 12 side).

In addition, instead of the second high frequency power supply 51 andthe third high frequency power supply 52, a pulsed power supplyconfigured to apply a pulse voltage other than the high frequency powerto the lower electrode 12 may also be used. Here, the pulse voltage is apulse-like voltage in which the magnitude of the voltage changesperiodically. The pulsed power supply may be a DC power supply. Thepulsed power supply may be configured to generate a pulse voltage byitself, or may be configured to include a DC power supply and a device(pulse generator) that pulses a voltage on a downstream side of the DCpower supply. In an example, the pulse voltage is applied to the lowerelectrode 12 so that a negative potential is generated in the wafer W.The pulse voltage may have a rectangular wave, a triangular wave, animpulse, or may have any other waveform. A frequency (pulse frequency)of the pulse voltage may be a frequency within the range of 100 kHz to 2MHz. In addition, the high frequency powers LF1 and LF2 or the pulsevoltage may be supplied or applied to a bias electrode provided insidethe electrostatic chuck 13.

The etching apparatus 1 further has a DC power supply 60, a switchingunit 61, a first RF filter 62, and a second RF filter 63 (correspondingto a third RF filter in the present disclosure). The DC power supply 60is electrically connected to the edge ring 14 from the DC power supply60 side via the switching unit 61, the second RF filter 63, and thefirst RF filter 62. The DC power supply 60 is connected to a groundpotential.

The DC power supply 60 is a power source for generating a negativepolarity DC voltage applied to the edge ring 14. In addition, the DCpower supply 60 is a variable DC power supply, and a height of the DCvoltage may be adjusted.

The switching unit 61 is configured to stop application of the DCvoltage from the DC power supply 60 to the edge ring 14. In addition, aperson skilled in the art may design a circuit configuration of theswitching unit 61 appropriately.

The first RF filter 62 and the second RF filter 63 each are filterswhich attenuate high frequency power. The first RF filter 62 attenuates,for example, the first high frequency power HF of 40 MHz from the firsthigh frequency power supply 50. The second RF filter 63 attenuates, forexample, the second high frequency power LF1 of 400 kHz from the secondhigh frequency power supply 51 or the third high frequency power LF2 of13 MHz from the third high frequency power supply 52.

In an example, the second RF filter 63 is configured to have variableimpedance. That is, the second RF filter 63 includes at least onevariable passive component and has variable impedance. The variablepassive component may be, for example, either a coil (inductor) or acondenser (capacitor). In addition, the variable element is not limitedto a coil and a condenser, and any variable impedance element, such asan element of a diode or the like may achieve the same function. Thenumber and position of the variable passive components may also beappropriately designed by those skilled in the art. The element itselfdoes not need to be variable, and for example, a plurality of elementseach having a fixed impedance value may be provided and impedance may bevaried by switching a combination of the elements having the fixedvalues using a switching circuit. In addition, a circuit configurationincluding the second RF filter 63 and a circuit configuration includingthe first RF filter 62 can be designed appropriately by a person skilledin the art.

The etching apparatus 1 further includes a bypass circuit 70. In anexample, the bypass circuit 70 is connected to a path 57 between thematching device 53 and the lower electrode 12 and a path 64 between thesecond RF filter 63 and the edge ring 14. In addition, the arrangementof the bypass circuit 70 is not limited thereto example. In addition,although the number of the bypass circuits 70 is one in this example,the bypass circuit may also be provided in plurality. A modification ofthe arrangement of the bypass circuit 70 and a modification of thecombination of the bypass circuit 70 are described below.

The bypass circuit 70 bypasses the high frequency power of a specificfrequency, thereby increasing the amount of power supplied to the edgering 14. Specifically, the bypass circuit 70 allows the high frequencypower of a frequency to be adjusted for an initial tilt angle, among agroup consisting of the first to third high frequency powers HF, LF1,and LF2 of a plurality of frequencies to be controlled for the tiltangle, to selectively pass therethrough. In addition, the bypass circuit70 adjusts a passage amount of the high frequency power (magnitude ofthe high frequency power), that is, the amount of power supplied to theedge ring 14.

As described above, the bypass circuit 70 has a frequency selectionfunction and a power passage amount determining function, but thecircuit configuration may be arbitrarily designed by a person skilled inthe art. In an example, the bypass circuit 70 may include a circuit thatblocks passage of high frequency power of a specific frequency, forexample, a coil (inductor) in order to achieve a frequency selectionfunction. In addition, the bypass circuit 70 may have an element whichdetermines the passage amount of high frequency power, for example, acondenser (capacitor) in order to achieve the power passage amountdetermination function.

The etching apparatus 1 further includes a lifting device 80 for liftingand lowering the edge ring 14. The lifting device 80 includes a liftingpin 81 ascending and descending, while supporting the edge ring 14, anda driving source 82 that lifts and lowers the lifting pin 81.

The lifting pin 81 elongates in a vertical direction from a lowersurface of the edge ring 14 and is provided through the electrostaticchuck 13, the lower electrode 12, the support member 17, and a bottom ofthe chamber 10. A space between the lifting pins 81 and the chamber 10is sealed to seal the inside of the chamber 10. At least the surface ofthe lifting pin 81 is formed of an insulator.

The driving source 82 is provided outside the chamber 10. The drivingsource 82 includes, for example, a motor, and lifts and lowers thelifting pin 81. That is, the edge ring 14 may be configured to be liftedand lowered between a state in which the edge ring 14 is mounted on theelectrostatic chuck 13 as illustrated in FIG. 2A and a state in whichthe edge ring 14 is spaced apart from the electrostatic chuck 13 asillustrated in FIG. 2B.

In addition, the etching apparatus 1 may further include a measurementdevice (not shown) which measures a self-bias voltage of the edge ring14 (or a self-bias voltage of the lower electrode 12 or the wafer W). Inaddition, a configuration of the measurement device may be appropriatelydesigned by those skilled in the art.

The above etching apparatus 1 includes the controller 100. Thecontroller 100 is, for example, a computer provided with a CPU or amemory, and has a program storage (not shown). A program for controllingetching in the etching apparatus 1 is stored in the program storage. Inaddition, the program may be recorded in a computer-readable storagemedium or may be installed in the controller 100 from the storagemedium. Further, the storage medium may be temporary or non-transitory.

<Etching Method>

Next, etching performed using the etching apparatus 1 configured asdescribed above is described.

First, the wafer W is loaded into the chamber 10, and the wafer W ismounted on the electrostatic chuck 13. Thereafter, by applying a DCvoltage to the first electrode 16 a of the electrostatic chuck 13, thewafer W is electrostatically adsorbed and held to the electrostaticchuck 13 by the Coulomb force. Further, after the wafer W is loaded, theinside of the chamber 10 is decompressed to a desired degree of vacuumby the exhaust device 42.

Next, a processing gas is supplied from the gas source group 30 throughthe shower head 20 to the processing space S. In addition, the firsthigh frequency power HF for plasma generation is supplied to the lowerelectrode 12 by the first high frequency power supply 50, and theprocessing gas is excited to generate plasma. At this time, the secondhigh frequency power LF1 and the third high frequency power LF2 forattracting ions may also be supplied by the second high frequency powersupply 51 and the third high frequency power supply 52. Then, the waferW is etched by the action of the generated plasma.

When the etching is terminated, first, the supply of the first highfrequency power HF from the first high frequency power supply 50 and thesupply of the processing gas by the gas source group 30 are stopped. Inaddition, when the high frequency powers LF1 and LF2 have been suppliedduring etching, the supply of the high frequency powers LF1 and LF2 isalso stopped. Next, the supply of a heat transfer gas to a rear surfaceof the wafer W is stopped, and the adsorption and holding of the wafer Wby the electrostatic chuck 13 is stopped.

Thereafter, the wafer W is unloaded from the chamber 10, and a series ofetching on the wafer W is terminated.

In the etching, plasma may be generated using only the second highfrequency power LF1 from the second high frequency power supply 51 oronly the third high frequency power LF2 from the third high frequencypower supply 52.

<Description of Tilt Angle>

A tilt angle is an inclination (angle) of a concave portion formed byetching in the edge region of the wafer W with respect to a thicknessdirection of the wafer W. The tilt angle is almost the same as aninclination of an incident direction of the ions to the edge region ofthe wafer W with respect to a vertical direction (incident angle ofions). In addition, in the following description, a radially inner(center side) direction with respect to the thickness direction(vertical direction) of the wafer W is referred to as an inner side, anda radially outer direction with respect to the thickness direction ofthe wafer W is referred to as an outer side.

FIGS. 3A and 3B are explanatory views illustrating a change in a shapeof a sheath due to consumption of an edge ring and the occurrence ofinclination in the incident direction of ions. In FIG. 3A, the edge ring14 indicated by the solid line illustrates the edge ring 14 in a statewithout the consumption. The edge ring 14 indicated by the dotted lineillustrates the edge ring 14 having a reduced thickness due to theconsumption. In addition, the sheath SH indicated by the solid line inFIG. 3A illustrates the shape of the sheath SH when the edge ring 14 isnot consumed. The sheath SH indicated by the dotted line illustrates theshape of the sheath SH when the edge ring 14 is consumed. In addition,in FIG. 3A, the arrows indicate the incident direction of the ions whenthe edge ring 14 is consumed.

As illustrated in FIG. 3A, in an example, when the edge ring 14 is notconsumed, the shape of the sheath SH is maintained flat above the waferW and the edge ring 14. Accordingly, ions are incident in a direction(vertical direction) substantially perpendicular to the front surface ofthe wafer W. Therefore, the tilt angle is 0 degrees.

Meanwhile, when the edge ring 14 is consumed and a thickness thereofdecreases, the thickness of the sheath SH decreases above the edgeregion of the wafer W and the edge ring 14, and the shape of the sheathSH is changed to a downwardly convex shape. As a result, the incidentdirection of the ions with respect to the edge region of the wafer W isinclined with respect to the vertical direction. In the followingdescription, a phenomenon in which the concave portion formed by etchinginclines toward the inner side when the incident direction of ions isinclined to the radially inner side (center side) with respect to thevertical direction is referred to as inner tilt. In FIG. 3B, theincident direction of ions is inclined toward the inner side by an angleθ1, and the concave portion is also inclined toward the inner side bythe angle θ1. The cause of inner tilt is not limited to wear of the edgering 14 described above. For example, when the bias voltage generated inthe edge ring 14 is lower than the voltage on the wafer W side, theinner tilt occurs in the initial state. Further, for example, the innertilt is intentionally set in the initial state of the edge ring 14, andthe tilt angle may be corrected by adjusting the driving amount of thelifting device 80, which will be described later.

In addition, as illustrated in FIGS. 4A and 4B, with respect to thecentral region of the wafer W, the thickness of the sheath SH mayincrease above the edge region of the wafer W and the edge ring 14, sothat the sheath SH may have an upwardly convex shape. For example, whena bias voltage generated in the edge ring 14 is high, the sheath SH mayhave an upward convex shape. In FIG. 4A, the arrows indicate theincident direction of ions. In the following description, a phenomenonin which the concave portion formed by etching is inclined toward theouter side when the incident direction of ions is inclined radiallyoutwardly with respect to the vertical direction is referred to as outertilt. In FIG. 4B, the incident direction of ions is inclined toward theouter side by an angle θ2 and the concave portion is also inclinedtoward the outer side by the angle θ2.

As described above, except for the case illustrated in FIGS. 4A and 4B,when the edge ring 14 is consumed by performing etching, as illustratedin FIGS. 3A and 3B, the tilt angle in the edge region of the wafer W isinclined toward the inner side. Due to this, in an example, the tiltangle is controlled and corrected to the outer side. The tilt angle iscontrolled by any one or a combination of adjustment of the impedance ofthe second RF filter 63, adjustment of the DC voltage from the DC powersupply 60, and adjustment of the driving amount of the lifting device80. In the following description, the impedance of the second RF filters63, the DC voltage from the DC power supply 60, and the driving amountof the lifting device 80 for controlling the tilt angle may becollectively referred to as “tilt control knob”. In addition, a specificmethod of controlling the tilt angle using the tilt control knob isdescribed below.

<Method of Adjusting Initial Tilt Angle>

As described above, when the tilt angle is controlled to the outer sideby the tilt control knob, an initial tilt angle in the initial statebefore etching is set to 0 (zero) degrees or an angle that is slightlyinner tilt in the initial state. Also, the initial state is beforeetching the wafer W, for example, when the etching apparatus 1 isoperated or when the etching apparatus 1 is operated after maintenance.

In the related art, adjustment of the initial tilt angle has beenperformed, for example, by adjusting the thickness of the edge ring 14.Alternatively, the initial tilt angle was adjusted by, for example,changing the material or thickness of the electrostatic chuck 13. Thatis, the initial tilt angle was adjusted by changing a deviceconfiguration (hardware).

Here, when the tilt angle is controlled for each of the first to thirdhigh frequency powers HF, LF1, and LF2 of a plurality of frequencies,for example, three frequencies, the thickness of a sheath generated bypower supplied to the edge ring 14 is different for each frequency.Then, as illustrated in FIG. 5 , an initial tilt angle differs for everyfirst to third frequencies. Hereinafter, the initial tilt angle withrespect to the first frequency is referred to as a first initial tiltangle, the initial tilt angle with respect to the second frequency isreferred to as a second initial tilt angle, and the initial tilt anglewith respect to the third frequency is referred to as a third initialtilt angle. In addition, the vertical axis of FIG. 5 represents a tiltangle, a positive side (upper side) of the tilt angle (Δ0) degree is anouter side, and a negative side (lower side) of the tilt angle Δ0 (zero)degree is an inner side. 90 degrees (described in parentheses) of thevertical axis indicates the thickness direction of the wafer W, and Δ0(zero) degrees indicate that there is no inclination from the thicknessdirection. The horizontal axis in FIG. 5 represents the adjustmentamount of the tilt control knob. In FIG. 5 , symbols of ●, ▴, and ▪indicate first to third initial tilt angles, respectively. In FIG. 5 ,straight lines elongated from the first to third initial tilt anglesschematically represent a state in which the tilt angle is changed byadjusting the tilt control knob, respectively.

In the case in which the first to third initial tilt angles aredifferent for each frequency as described above, the initial tilt angleof another frequency cannot be adjusted only by changing the deviceconfiguration as in the related art even if the initial tilt angle ofone frequency is adjusted. That is, the entire first to third initialtilt angles cannot be properly adjusted. Further, when the first tothird initial tilt angles are different for each frequency, even if thetilt angle is controlled using the tilt control knob, the tilt angle maynot be properly controlled, for example, to 0 (zero) degrees.

Therefore, in the etching apparatus 1 of the present embodiment, theinitial tilt angle is adjusted for each frequency using the bypasscircuit 70. That is, the bypass circuit 70 bypasses the high frequencypower of a specific frequency to increase the amount of power suppliedto the edge ring 14, thereby adjusting the initial tilt angle in theedge region of the wafer W. Specifically, the bypass circuit 70 allowsthe high frequency power of the frequency to be adjusted for the initialtilt angle, among the high frequency powers of a plurality offrequencies to be controlled for the tilt angle, to selectively passtherethrough. In addition, the bypass circuit 70 adjusts the passageamount of the high frequency power, that is, the amount of powersupplied to the edge ring 14.

For example, in the example illustrated in FIG. 5 , the first to thirdinitial tilt angles are different from each other, and the secondinitial tilt angle and the third initial tilt angle are to be adjusted.In this case, the second high frequency power LF1 and the third highfrequency power LF2, among the first to third high frequency powers HF,LF1 and LF2, are allowed to pass through the edge ring 14 by the bypasscircuit 70. At this time, the passage amount of the second highfrequency power LF1 and the passage amount of the third high frequencypower LF2 are set to the passage amounts according to an adjustmentwidth of the initial tilt angle. Then, the supply amounts of the secondhigh frequency power LF1 and the third high frequency power LF2 suppliedto the edge ring 14 increase, so that the second tilt angle and thethird initial tilt angle are adjusted to the outer side as illustratedin FIG. 6 . In addition, the first to third initial tilt angles may beadjusted to be substantially the same.

As described above, in the present embodiment, at the initial state,such as when the etching apparatus 1 is manufactured or when the etchingapparatus 1 is adjusted, the first to third initial tilt angles may beindependently adjusted using the bypass circuit 70, and thus, thesefirst to third initial tilt angles may be adjusted to be substantiallythe same. As a result, when etching is performed thereafter, the tiltangle for each of the first to third frequencies may be appropriatelyadjusted to, for example, 0 (zero) degrees by adjusting the tilt controlknob.

In addition, when the first to third initial tilt angles are adjusted inthe initial state, the first to third initial tilt angles are basicallynot changed in subsequent etching. Further, according to the presentembodiment, in the initial state, since the first to third initial tiltangles are adjusted using the bypass circuit 70 different from the tiltcontrol knob, a control range of the tilt angle may be widened by thetilt control knob.

FIG. 7 is an explanatory view illustrating the effect of widening acontrol range of a tilt angle, in which (a) illustrates a control rangeof a tilt angle in Comparative Example and (b) illustrates a controlrange of a tilt angle in the example of the present embodiment. That is,(a) of FIG. 7 corresponds to the tilt angle illustrated in FIG. 5 , and(b) of FIG. 7 corresponds to the tilt angle illustrated in FIG. 6 . Inaddition, in FIG. 7 , the dotted line represents a control range of atilt angle by a tilt control knob. Meanwhile, the solid line in whichboth ends are indicated by circles is a control range of a tilt angle inwhich the final tilt angle is within an allowable range, in other words,a control range of a tilt angle that may be actually used.

As illustrated in (a) of FIG. 7 , in Comparative Example, the first tothird initial tilt angles are not individually adjusted, and the firstto third initial tilt angles are different. In this case, since thesecond initial tilt angle is shifted to the inner side, the actuallyusable control range of the tilt angle (solid line) with respect to thecontrol range of the tilt angle by the tilt control knob (dashed line)is narrowed. In addition, since the third initial tilt angle is shiftedto the inner side further than the second tilt angle, the actuallyusable control range (solid line) of the tilt angle is further narrowed.As described above, since the first to third initial tilt angles are notproperly adjusted, the control range of the tilt angle is narrowed, andthe effect of controlling the tilt angle by the tilt control knob isreduced.

In contrast, as illustrated in (b) of FIG. 7B, in an embodiment, thefirst to third initial tilt angles are adjusted to be substantially thesame using the bypass circuit 70. That is, adjustment of the initialtilt angle may be performed using only the bypass circuit 70, andsubsequent control of the tilt angle may be performed using only thetilt control knob. In this case, since the second initial tilt angle isshifted to the outer side and adjusted to a desired angle, the actuallyusable control range (solid line) of the tilt angle may be widened. Inaddition, since the third initial tilt angle is shifted to the outerside further than the second tilt angle and adjusted to a desired angle,the actually usable control range (solid line) of the tilt angle may befurther widened. As described above, in the embodiment, the controlrange of the tilt angle may be widened by maximizing the control rangeof the tilt angle by the tilt control knob.

In addition, in the present embodiment, only the tilt angles for all thefirst to third high frequency powers HF, LF1, and LF2, among the firstto third high frequency powers HF, LF1, and LF2 of three frequencies,are controlled, but the number of control targets is not limitedthereto. For example, the disclosed technology may be applied even to acase in which a tilt angle for high frequency powers of two frequenciesis a control target. In other words, when a tilt angle for highfrequency powers of two or more frequencies is a control target, thedisclosed technology is useful.

In addition, even when a tilt angle with respect to a high frequencypower of one frequency is a control target, the technique of the presentdisclosure is applicable. In the related art, the initial tilt angle hasbeen adjusted by changing the device configuration as described above.However, in the present embodiment, the initial tilt angle is adjustedusing the bypass circuit 70, and thus, the initial tilt angle may beeasily adjusted.

<Variation of Bypass Circuit>

Next, variations in the arrangement and combination of bypass circuitsare described.

[Arrangement of Bypass Circuit]

In the above embodiment, as illustrated in FIG. 2A, the bypass circuit70 is connected to the path 57 between the matching device 53 and thelower electrode 12 and the path 64 between the second RF filter 63 andthe edge ring 14, but the arrangement of the bypass circuit 70 is notlimited thereto. The bypass circuit 70 is connected to the same positionas the matching device 53 or to the path 57 between the matching device53 and the lower electrode 12. The reason for locating the bypasscircuit 70 in this way is to include a downstream side of the bypasscircuit 70 in a matching range. The bypass circuit 70 is also connectedto the RF filters 62 and 63 or to the path 64 between the RF filters 62and 63 and the edge ring 14.

For example, as illustrated in FIG. 8A, the bypass circuit 70 may beprovided inside the second RF filter 63. Further, for example, asillustrated in FIG. 8B, the bypass circuit 70 may be provided inside thefirst RF filter 62. In addition, although not illustrated, the bypasscircuit 70 may be provided inside the matching device 53. Furthermore,although not shown, the bypass circuit 70 may be connected to thematching device 53 and the second RF filter 63 or may be connected tothe matching device 53 and the DC power supply 60. As such, the bypasscircuit 70 is not dependent on the arrangement.

[Combination of Bypass Circuit]

In the above embodiment, as illustrated in FIG. 2A, the bypass circuit70 is provided in common for the first to third high frequency powersHF, LF1, and LF2 of a plurality of frequencies, but a combination of thebypass circuit 70 is not limited thereto. For example, the bypasscircuit 70 may be independently provided for each of the first to thirdhigh frequency powers HF, LF1, and LF2 of three frequencies. Also, forexample, the bypass circuit 70 does not need to be provided in all ofthe first to third high frequency powers HF, LF1, and LF2 to becontrolled for the tilt angle. For example, for high frequency powers ofsome frequencies, the initial tilt angle may be adjusted by using thebypass circuit 70, and for high frequency powers of other frequencies,and the initial tilt angle may be adjusted by changing the deviceconfiguration as in the related art. Alternatively, one bypass circuit70 may be provided for high frequency powers of two or more frequencies.When these frequencies are close, it is not necessary to provide aplurality of bypass circuits 70. The combination of these bypasscircuits 70 is arbitrary.

For example, as illustrated in FIG. 9A, a bypass circuit 70 a allowingthe first high frequency power HF to pass therethrough, a bypass circuit70 b allowing the second high frequency power LF1 to pass therethrough,and a bypass circuit 70 c allowing the third high frequency power LF2 topass therethrough may be provided. This is a case in which all of thefirst to third initial tilt angles are adjusted. Moreover, asillustrated in FIG. 9B, only the bypass circuit 70 a allowing the firsthigh frequency power HF to pass therethrough and the bypass circuit 70 ballowing the second high frequency power LF1 to pass therethrough may beprovided. This is a case of adjusting the first initial tilt angle andthe second initial tilt angle. Alternatively, as illustrated in FIG. 9C,only the bypass circuit 70 b allowing the second high frequency powerLF1 to pass therethrough and the bypass circuit 70 c allowing the thirdhigh frequency power LF2 to pass therethrough may be provided. This is acase of adjusting the second initial tilt angle and the third initialtilt angle.

For example, as illustrated in FIG. 9D, a bypass circuit 70 d allowingthe first high frequency power HF and the second high frequency powerLF1 to pass therethrough and a bypass circuit 70 c allowing the thirdhigh frequency power LF2 to pass therethrough may be provided. Thebypass circuit 70 d adjusts the first initial tilt angle and the secondinitial tilt angle. In addition, as illustrated in FIG. 9E, only thebypass circuit 70 d allowing the first high frequency power HF and thesecond high frequency power LF1 to pass therethrough may be provided.Alternatively, only the bypass circuit 70 c allowing the third highfrequency power LF2 to pass therethrough may be provided.

<Tilt Angle Control Method>

Next, with respect to the etching described above, a method ofcontrolling a tilt angle using the tilt control knob is described. Thetilt control knob is any one or a combination of the adjustment of theimpedance of the second RF filter 63, the adjustment of the DC voltagefrom the DC power supply 60, and the driving amount of the liftingdevice 80, that is, the following (1) to (7). Also, the tilt angle iscontrolled by controlling an incident angle of the ions using the tiltcontrol knob.

(1) Adjustment of impedance

(2) Adjustment of DC voltage

(3) Adjustment of driving amount

(4) Adjustment of impedance and DC voltage

(5) Adjustment of impedance and driving amount

(6) Adjustment of DC voltage and driving amount

(7) Adjustment of impedance, DC voltage, and driving amount

(1) Adjustment of Impedance

A case of adjusting the impedance of the second RF filter 63 isdescribed. FIG. 10 is an explanatory view illustrating a relationshipbetween the impedance of the second RF filter 63 and a tilt anglecorrection angle (hereinafter, referred to as “tilt correction angle”).In FIG. 10 , the vertical axis represents the tilt correction angle andthe horizontal axis represents the impedance of the second RF filter 63.As illustrated in FIG. 10 , as the impedance of the second RF filter 63increases, the tilt correction angle increases. In the exampleillustrated in FIG. 10 , the tilt correction angle is increased byincreasing the impedance, but it is also possible to reduce the tiltcorrection angle by increasing the impedance by the configuration of thesecond RF filter 63. The relationship between the impedance and the tiltcorrection angle depends on the design of the second RF filter 63, andthus is not limited.

The controller 100 sets the impedance of the second RF filter 63 by aconsumption amount (a reduction amount from an initial value of thethickness of the edge ring 14) of the edge ring 14 estimated from aprocess condition (e.g., a processing time) of etching using apredetermined function or table. That is, the controller 100 determinesthe impedance of the second RF filter 63 by inputting the consumptionamount of the edge ring 14 into the function or referring to the tableusing the consumption amount of the edge ring 14. Then, the controller100 changes a voltage generated in the edge ring 14 by changing theimpedance of the second RF filter 63.

In addition, the consumption amount of the edge ring 14 may be estimatedbased on an etching time of the wafer W, the number of processed wafersW, the thickness of the edge ring 14 measured by a measurement device, achange in mass of the edge ring 14 measured by a measurement device, achange in electrical characteristics (e.g., a voltage or current valueof a certain point near the edge ring 14) near the edge ring 14 measuredby a measurement device, or a change in electrical characteristics(e.g., a resistance value of the edge ring 14) of the edge ring 14measured by a measurement device. In addition, the impedance of thesecond RF filter 63 may be adjusted according to an etching time of thewafer W or the number of processed wafers W, regardless of theconsumption amount of the edge ring 14. In addition, the impedance ofthe second RF filter 63 may be adjusted according to an etching time ofthe wafer weighted by the high frequency power or the number ofprocessed wafers W.

A detailed method of controlling the tilt angle by adjusting theimpedance of the second RF filter 63 as described above is described.First, the edge ring 14 is installed on the electrostatic chuck 13. Atthis time, for example, above the edge region of the wafer W and theedge ring 14, the sheath shape is flat and the tilt angle is 0 (zero)degree.

Next, etching is performed on the wafer W. With the lapse of time duringwhich etching is performed, the edge ring 14 is consumed and a thicknessthereof decreases. Then, as illustrated in FIG. 3A, above the edgeregion of the wafer W and the edge ring 14, the thickness of the sheathSH is reduced, and the tilt angle changes to the inner side.

Therefore, the impedance of the second FR filter 63 is adjusted.Specifically, the impedance of the second RF filter 63 is adjustedaccording to the consumption amount of the edge ring 14. Then, asillustrated in FIG. 10 , the tilt correction angle increases, and thetilt angle inclined toward the inner side may be changed to the outerside. That is, the shape of the sheath is controlled above the edge ring14 and the edge region of the wafer W, the inclination of the incidentdirection of ions to the edge region of the wafer W is reduced, and thetilt angle is controlled. Also, as described above, when the controller100 adjusts the second RF filter 63 to the set impedance, the tilt anglemay be corrected to 0 (zero) degrees by adjusting the tilt correctionangle to the target angle θ3. As a result, a concave portionsubstantially parallel to the thickness direction of the wafer W isformed over the entire area of the wafer W.

(2) Adjustment of DC Voltage

A case of adjusting the DC voltage from the DC power supply 60 isdescribed. FIG. 11 is an explanatory view illustrating a relationshipbetween a DC voltage from the DC power supply 60 and a tilt correctionangle. In FIG. 11 , the vertical axis represents a tilt correction angleand the horizontal axis represents the DC voltage from the DC powersupply 60. As illustrated in FIG. 11 , as the DC voltage from the DCpower supply 60 increases, the tilt correction angle increases.

In the DC power supply 60, the DC voltage applied to the edge ring 14 isset to a voltage of a negative polarity, i.e., −(|Vdc|+ΔV) having thesum of the self-bias voltage Vdc and a set value ΔV, as an absolutevalue. The self-bias voltage Vdc is a self-bias voltage of the wafer W,and also, is a self-bias voltage of the lower electrode 12 when one orboth of the high frequency powers have been supplied and when the DCvoltage from the DC power supply 60 is not applied to the lowerelectrode 12. The set value ΔV is provided by the controller 100.

The controller 100 sets the DC voltage from the DC power supply 60 fromthe consumption amount of the edge ring 14, similarly to the setting ofthe impedance of the second RF filter 63 described above. That is, theset value ΔV is determined.

In determining the set value ΔV, the controller 100 may use a differencebetween an initial thickness of the edge ring 14 and a thickness of theedge ring 14 actually measured using a measurement device, such as alaser measurement device or a camera, for example, as the consumptionamount of the edge ring 14. Alternatively, the consumption amount of theedge ring 14 may be estimated from a change in the mass of the edge ring14 measured by a measuring device such as a mass meter. Alternatively,the controller 100 may estimate the consumption amount of the edge ring14 from a specific parameter using another predetermined function ortable to determine the set value ΔV. This specific parameter may be anyone of the self-bias voltage Vdc, a peak value Vpp of any one of thefirst to third high frequency powers HF, LF1, and LF2, load impedance,the edge ring 14, or electrical characteristics of the periphery of theedge ring 14. The edge ring 14 or the electrical characteristics of theperiphery of the edge ring 14 may be any one of a voltage, a currentvalue at the edge ring 14 or any location around the edge ring 14, and aresistance value including the edge ring 14. Another function or tableis predefined to determine a relationship between a specific parameterand the consumption amount of the edge ring 14. In order to estimate theconsumption amount of the edge ring 14, before the actual execution ofetching or during maintenance of the etching apparatus 1, the etchingdevice 1 is operated under measurement conditions for estimating theconsumption amount, that is, under the setting of the first highfrequency power HF, the second high frequency power LF1, the third highfrequency power LF2, the pressure in the processing space S, and a flowrate of the processing gas supplied to the processing space S. Then, thespecific parameter is acquired, and the consumption amount of the edgering 14 is specified by inputting the specific parameter into the otherfunction or referring to the table using the specific parameter.

In the etching apparatus 1, during etching, that is, during a period inwhich any one of the first to third high frequency powers HF, LF1, andLF2 or a plurality of high frequency powers is supplied, a DC voltage isapplied from the DC power 60 to the edge ring 14. Thereby, the shape ofthe sheath above the edge ring 14 and the edge region of the wafer W iscontrolled so that inclination of the incident direction of ions to theedge region of the wafer W is reduced and the tilt angle is controlled.As a result, a concave portion substantially parallel to the thicknessdirection of the wafer W is formed over the entire area of the wafer W.

More specifically, during etching, the self-bias voltage Vdc is measuredby a measurement device (not shown). Further, a DC voltage is applied tothe edge ring 14 from the DC power supply 60. A value of the DC voltageapplied to the edge ring 14 is −(|Vdc|+ΔV) as described above. |Vdc| isan absolute value of the measured value of the self-bias voltage Vdcacquired by the measurement device immediately before, and ΔV is a setvalue determined by the controller 100. In this way, the DC voltageapplied to the edge ring 14 from the self-bias voltage Vdc measuredduring etching is determined. Then, even if a change occurs in theself-bias voltage Vdc, the DC voltage generated by the DC power supply60 is corrected, and the tilt angle is appropriately corrected.

In the etching apparatus 1, when the edge ring 14 is consumed, the DCvoltage set by the controller 100 is applied from the DC power supply 60to the edge ring 14. Thereby, the shape of the sheath above the edgering 14 and the edge region of the wafer W is controlled and theinclination of the incident direction of ions to the edge region of thewafer W is reduced, so that the tilt angle is controlled. Then, asillustrated in FIG. 11 , a tilt correction angle may be adjusted to atarget angle θ3, and the tilt angle may be adjusted to 0 degrees.

(3) Adjustment of Driving Amount

The case of adjusting the driving amount of the lifting device 80 isdescribed. FIG. 12 is an explanatory view illustrating a relationshipbetween a driving amount of the lifting device 80 and a tilt correctionangle. In FIG. 12 , the vertical axis represents the tilt correctionangle and the horizontal axis represents the driving amount of thelifting device 80. As illustrated in FIG. 12 , when the driving amountof the lifting device 80 increases, the tilt correction angle increases.

The controller 100 sets the driving amount of the lifting device 80 fromthe consumption amount of the edge ring 14, similarly to the setting ofthe impedance of the second RF filter 63 described above. Also, forexample, the driving amount of the lifting device 80 is increasedaccording to the consumption amount of the edge ring 14, to lift theedge ring 14.

In the etching apparatus 1, when the edge ring 14 is consumed, the edgering 14 is lifted based on the driving amount set by the controller 100.Thereby, the shape of the sheath above the edge ring 14 and the edgeregion of the wafer W is controlled and the inclination of the incidentdirection of ions to the edge region of the wafer W is reduced, therebycontrolling the tilt angle. In this way, as illustrated in FIG. 12 , thetilt correction angle may be adjusted to the target angle θ3, and thetilt angle may be set to 0 (zero) degrees.

(4) Adjustment of Impedance and DC Voltage

The case in which the impedance of the second RF filter 63 and the DCvoltage from the DC power supply 60 are combined and adjusted isdescribed. FIG. 13 is an explanatory view illustrating a relationshipamong the impedance of the second RF filter 63, the DC voltage from theDC power supply 60, and a tilt correction angle. In FIG. 13 , thevertical axis represents the tilt correction angle, and the horizontalaxis represents the impedance of the second RF filter 63.

As illustrated in FIG. 13 , first, the impedance of the second RF filter63 is adjusted, and a tilt angle is corrected. Next, when the impedancereaches a predetermined value, for example, an upper limit value, the DCvoltage from the DC power supply 60 is adjusted and the tilt correctionangle is adjusted to the target angle θ3, and the tilt angle is set to 0(zero). In this case, the number of times of adjustment of the impedanceand adjustment of the DC voltage may be reduced, thereby simplifying theoperation of the tilt angle control.

Here, resolution of the tilt angle correction by the adjustment of theimpedance and resolution of the tilt angle correction by the adjustmentof the DC voltage depend on the performance of the second RF filter 63and the DC power supply 60. The resolution of the tilt angle correctionis the amount of correction of the tilt angle in one adjustment of theimpedance or the DC voltage. Also, for example, when the resolution ofthe second RF filter 63 is higher than that of the DC power supply 60,in the present embodiment, since the tilt angle of corrected byadjusting the impedance of the second RF filter 63, the resolution ofthe overall tilt angle correction may be improved.

As described above, the adjustment range of the tilt angle may beenlarged by adjusting the impedance of the second RF filter 63 andadjusting the DC voltage from the DC power supply 60. Therefore, thetilt angle may be appropriately controlled, that is, the incidentdirection of ions may be appropriately adjusted, and thus, etching maybe performed uniformly.

In the example illustrated in FIG. 13 , the adjustment of the impedanceand the adjustment of the DC voltage are performed once to adjust thetilt correction angle to the target angle θ3, but the number of theadjustment of the impedance and the adjustment of the DC voltage are notlimited thereto. For example, as illustrated in FIG. 14 , the adjustmentof the impedance and the adjustment of the DC voltage may be performed aplurality of times. Even in such a case, the effect similar to that ofthe present embodiment may be achieved.

In addition, in the example illustrated in FIG. 13 and FIG. 14 , afterthe impedance of the second RF filter 63 is adjusted, the DC voltagefrom the DC power supply 60 is adjusted, but this order may be reversed.In this case, first, the tilt angle is corrected by adjusting the DCvoltage from the DC power supply 60. At this time, if an absolute valueof the DC voltage is too high, a discharge may occur between the wafer Wand the edge ring 14. Therefore, there is a limit to the DC voltage thatmay be applied to the edge ring 14. Thus, when the DC voltage reaches apredetermined value, for example, an upper limit value afterwards, thetilt correction angle is adjusted to the target angle θ3 by adjustingthe impedance of the second RF filter 63, and the tilt angle is set to 0(zero) degrees. Also in such a case, the effect similar to that of thepresent embodiment may be achieved.

In addition, in the above embodiment, although the adjustment of theimpedance of the second RF filter 63 and the adjustment of the DCvoltage from the DC power supply 60 are performed separately, theadjustment of the impedance and the adjustment of the DC voltage may beperformed simultaneously.

(5) Adjustment of Impedance and Driving Amount

A case in which the impedance of the second RF filter 63 and the drivingamount of the lifting device 80 are combined and adjusted is described.FIG. 15 is an explanatory view illustrating a relationship among theimpedance of the second RF filter 63, the driving amount of the liftingdevice 80, and the tilt correction angle. In FIG. 15 , the vertical axisrepresents the tilt correction angle and the horizontal axis representsthe impedance of the second RF filter 63.

As illustrated in FIG. 15 , first, the tilt angle is corrected byadjusting the impedance of the second RF filter 63. Next, when theimpedance reaches a predetermined value, for example, an upper limitvalue, the tilt correction angle is adjusted to the target angle 83 andthe tilt angle is set to 0 (zero) degree by adjusting the driving amountof the lifting device 80.

Further, the adjustment of the impedance and the adjustment of thedriving amount may be performed a plurality of times. In addition, aftercorrecting the tilt angle by adjusting the driving amount, the tiltcorrection angle may be adjusted to the target angle 83 by adjusting theimpedance. Alternatively, the adjustment of the impedance and theadjustment of the driving amount may be performed simultaneously.

(6) Adjustment of DC Voltage and Driving Amount

A case in which the DC voltage from the DC power supply 60 and theimpedance of the second RF filter 63 are combined and adjusted isdescribed. FIG. 16 is an explanatory view illustrating a relationshipamong the DC voltage from the DC power supply 60, the driving amount ofthe lifting device 80, and the tilt correction angle. In FIG. 16 , thevertical axis represents the tilt correction angle and the horizontalaxis represents the DC voltage from the DC power supply 60.

As illustrated in FIG. 16 , first, the DC voltage from the DC powersupply 60 is adjusted to correct the tilt angle. Next, when the DCvoltage reaches a predetermined value, for example, an upper limitvalue, the driving amount of the lifting device 80 is adjusted to adjustthe tilt correction angle to the target angle 83, and the tilt angle isset to 0 (zero).

Further, the adjustment of the DC voltage and the adjustment of thedriving amount may be performed a plurality of times. In addition, aftercorrecting the tilt angle by adjusting the driving amount, the tiltcorrection angle may be adjusted to the target angle 83 by adjusting theDC voltage. Alternatively, the adjustment of the DC voltage and theadjustment of the driving amount may be performed simultaneously.

(7) Adjustment of Impedance, DC Voltage, and Driving Amount

The case in which the impedance of the second RF filter 63, the DCvoltage from the DC power supply 60, and the driving amount of thelifting device 80 are combined and adjusted is described. FIG. 17 is anexplanatory view illustrating a relationship among the impedance of thesecond RF filter 63, the DC voltage from the DC power supply 60, thedriving amount of the lifting device 80, and the tilt correction angle.The vertical axis of FIG. 17 indicates the tilt correction angle and thehorizontal axis represents the impedance of the second RF filter 63.

As illustrated in FIG. 17 , first, a tilt angle is corrected byadjusting the impedance of the second RF filter 63. Next, when theimpedance reaches a predetermined value, for example, an upper limitvalue, the tilt angle is corrected by adjusting the DC voltage from theDC power supply 60. In addition, when an absolute value of the DCvoltage reaches a predetermined value, for example, an upper limitvalue, a tilt correction angle is adjusted to the target angle 83 byadjusting the driving amount of the lifting device 80, and the tiltangle is set to 0 (zero) road.

In addition, when controlling the tilt angle, the combination of theadjustment of the impedance of the second RF filter 63, the DC voltagefrom the DC power supply 60, and the adjustment of the driving amount ofthe lifting device 80 may be arbitrarily designed. In addition, althoughthe adjustment of the impedance of the second RF filter 63, the DCvoltage from the DC power supply 60, and the adjustment of the drivingamount of the lifting device 80 are separately performed, theseadjustments may be performed simultaneously.

In addition, although the DC power supply 60 is connected to the edgering 14 via the switching unit 61, the first RF filter 62, and thesecond RF filter 63, a power system applying a DC voltage to the edgering 14 is not limited thereto. For example, the DC power supply 60 maybe electrically connected to the edge ring 14 via the switching unit 61,the second RF filter 63, the first RF filter 62, and the lower electrode12. In this case, the lower electrode 12 and the edge ring 14 aredirectly electrically coupled, and a self-bias voltage of the edge ring14 is equal to a self-bias voltage of the lower electrode 12.

Here, when the lower electrode 12 and the edge ring 14 are directlyelectrically coupled, the thickness of the sheath on the edge ring 14cannot be adjusted due to capacity below the edge ring 14 determined bya hard structure, and thus, an outer tilt state may occur even when a DCvoltage is not applied. In this regard, in the present disclosure, sincethe tilt angle may be controlled by adjusting the DC voltage from the DCpower supply 60, the impedance of the second RF filter 63, and thedriving amount of the lifting device 80, the tilt angle can be adjustedto 0 (zero) degrees by changing the tilt angle to the inner side.

Other Embodiments

In the above embodiment, the adjustment of the impedance of the secondRF filter 63, the adjustment of the DC voltage from the DC power supply60, and the adjustment of the driving amount of the lifting device 80are performed according to the consumption amount of the edge ring 14,but a timing of adjustment of the impedance, DC voltage, and drivingamount is not limited thereto. For example, the driving amount, theimpedance, and the DC voltage may be adjusted according to a processingtime of the wafer W. Alternatively, the adjustment timing of the drivingamount, impedance, and DC voltage may be determined by combining, forexample, the processing time of the wafer W and predeterminedparameters, such as high frequency power, for example.

Other Embodiments

In the above embodiment, the impedance of the second RF filter 63 isvaried, but the impedance of the first RF filter 62 may be varied, andthe impedance of both the RF filters 62 and 63 may be varied. Inaddition, although the two RF filters 62 and 63 are provided for the DCpower supply 60 in the above embodiment, the number of RF filters is notlimited thereto, and may be one, for example. In addition, in the aboveembodiment, although the impedance is varied by forming some elements ofthe second RF filter 63 as variable elements, the structure in which theimpedance is varied is not limited thereto. For example, a devicecapable of changing the impedance of the RF filter may be connected to avariable or fixed impedance RF filter. That is, the RF filter having avariable impedance may be configured with an RF filter and a deviceconnected to this RF filter and capable of changing the impedance of theRF filter.

<Configuration of Bypass Circuit and Tilt Control Knob>

As described above, in the initial state, after the initial tilt angleis adjusted by the bypass circuit 70, the tilt angle is controlled usingthe tilt control knob in etching. Next, a configuration for performingadjustment of the initial tilt angle and control of the tilt angle isdescribed. As the structure, the following (1) to (8) may be mentioned.

(1) Bypass circuit 70 and second RF filter 63

(2) Bypass circuit 70 and DC power supply 60

(3) Bypass circuit 70 and lifting device 80

(4) Bypass circuit 70, second RF filter 63, and DC power supply 60

(5) Bypass circuit 70, second RF filter 63, and lifting device 80

(6) Bypass circuit 70, DC power supply 60, and lifting device 80

(7) Bypass circuit 70, second RF filter 63, DC power supply 60, andlifting device 80

(8) Bypass circuit 70 and DC pulsed power supply

(1) Bypass Circuit 70 and Second RF Filter 63

In this configuration, after the initial tilt angle is adjusted by thebypass circuit 70 in the initial state, the impedance of the second RFfilter 63 is adjusted in the etching to control the tilt angle. Anexample of this configuration may be the configuration illustrated inFIG. 2A. In addition, as illustrated in FIG. 18 , an example of thisconfiguration may be a configuration in which the DC power supply 60,the switching unit 61, the first RF filter 62, and the second RF filter63 are omitted in the configuration illustrated in FIG. 2A. In thiscase, instead of the first RF filter 62 and the second RF filter 63, afirst variable passive component 62 a and a second variable passivecomponent 63 a are provided, respectively. The first variable passivecomponent 62 a and the second variable passive component 63 a arearranged in this order from the edge ring 14 side. The second variablepassive component 63 a is connected to a ground potential. That is, thesecond variable passive component 63 a is not connected to each of thefirst high frequency power supply 50, the second high frequency powersupply 51, and the third high frequency power supply 52. In addition, asan example of this configuration, in the configuration illustrated inFIGS. 2 and 18 , the lifting device 80 may be omitted.

In one example, at least one of the first variable passive component 62a and the second variable passive component 63 a is configured to bevariable in impedance. The first variable passive component 62 a and thesecond variable passive component 63 a may be either coils (inductors)or condensers (capacitors), for example. In addition, the same functioncan be achieved with any variable impedance element such as a diode, notlimited to a coil or a condenser. The number and positions of the firstvariable passive component 62 a and the second variable passivecomponent 63 a can also be appropriately designed by those skilled inthe art. Furthermore, the elements themselves do not have to bevariable. For example, a plurality of elements with fixed impedancevalues may be provided, and a switching circuit may be used to switchthe combination of the elements with fixed impedance values to vary theimpedance. A circuit configuration including the first variable passivecomponent 62 a and a circuit configuration including the second variablepassive component 63 a can be appropriately designed by those skilled inthe art.

In this embodiment, the bypass circuit 70 is connected to the path 57between the matching device 53 and the lower electrode 12 and the path64 between the second variable passive component 63 a and the edge ring14, but the arrangement of the bypass circuit 70 is not limited to this.For example, although not shown, the bypass circuit 70 may be connectedto the matching device 53 and the second variable passive component 63a.

(2) Bypass Circuit 70 and DC Power Supply 60

In this configuration, after the initial tilt angle is adjusted by thebypass circuit 70 in the initial state, the tilt angle is controlled byadjusting the DC voltage from the DC power supply 60 in etching. Anexample of this configuration may be the configuration of FIG. 2A. Inaddition, an example of this configuration may be a configuration inwhich the lifting device 80 is omitted in the configuration illustratedin FIG. 2A.

(3) Bypass Circuit 70 and Lifting Device 80

In this configuration, after the initial tilt angle is adjusted by thebypass circuit 70 in the initial state, the driving amount of thelifting device 80 is adjusted in the etching to control the tilt angle.An example of this configuration may be the configuration illustrated inFIG. 2A. Moreover, as illustrated in FIG. 19 , an example of thisconfiguration may be a configuration in which the DC power supply 60,the switching unit 61, the first RF filter 62, and the second RF filterare omitted in the configuration illustrated in FIG. 2A. In this case,the bypass circuit 70 is connected to the path 64 which is connected tothe edge ring 14.

(4) Bypass Circuit 70, Second RF Filter 63, and DC Power Supply 60

In this configuration, after adjusting the initial tilt angle by thebypass circuit 70 in the initial state, in the etching, the tilt angleis controlled by adjusting the impedance of the second RF filter 63 andthe DC voltage from the DC power supply 60. An example of thisconfiguration may be the configuration illustrated in FIG. 2A. Inaddition, an example of this configuration may be a configuration inwhich the lifting device 80 is omitted in the configuration illustratedin FIG. 2A.

(5) Bypass Circuit 70, Second RF Filter 63, and Lifting Device 80

In this configuration, after adjusting the initial tilt angle by thebypass circuit 70 in the initial state, the tilt angle is controlled byadjusting the impedance of the second RF filter 63 and the drivingamount of the lifting device 80. An example of this configuration may bethe configuration illustrated in FIG. 2A. Also, an example of thisconfiguration may be the configuration illustrated in FIG. 18 .

(6) Bypass Circuit 70, DC Power Supply 60, and Lifting Device 80

In this configuration, after adjusting the initial tilt angle by thebypass circuit 70 in the initial state, the tilt angle is controlled byadjusting the DC voltage from the DC power supply 60 and the drivingamount of the lifting device 80 during etching. An example of thisconfiguration may be the configuration illustrated in FIG. 2A.

(7) Bypass Circuit 70, Second RF Filter 63, DC Power Supply 60, andLifting Device 80

In this configuration, after the initial tilt angle is adjusted by thebypass circuit 70 in the initial state, the tilt angle is controlled byadjusting the impedance of the second RF filter 63, the DC voltage fromthe DC power supply 60, and the driving amount of the lifting device 80.An example of this configuration may be the configuration illustrated inFIG. 2A.

(8) Bypass Circuit 70 and DC Pulsed Power Supply

In this configuration, after the initial tilt angle is adjusted by thebypass circuit 70 with respect to the initial state, the tilt angle iscontrolled by applying a pulsed negative voltage to the edge ring 14 inetching.

As illustrated in FIG. 20 , an example of this configuration may be aconfiguration in which the pulsed power supply 65 is disposed instead ofthe DC power supply 60 in the configuration illustrated in FIG. 2A. Thepulsed power supply 65 may be configured to apply a pulse voltage byitself, or may be configured to include a DC power supply and a device(pulse generator) pulsing a voltage on a downstream side of the DC powersupply. In this case, the bypass circuit 70 may be connected to the path57 between the matching device 53 and the lower electrode 12 and a path66 between the edge ring 14 and the pulsed power supply 65.Alternatively, although not shown, the bypass circuit 70 may beconnected to the matching device 53 and a third RF filter 67 to bedescribed later. Further, although not shown, when the edge ring 14 andthe pulsed power supply 65 are not connected, the bypass circuit 70 maybe directly connected to the edge ring 14. In this case, the liftingdevice 80 may be omitted.

The pulsed power supply 65 is a power supply that applies a pulse-shapednegative polarity voltage to the edge ring 14. The pulsed power supply65 is coupled to the edge ring 14 in the path 66 between the edge ring14 and the pulsed power supply 65. The path 66 is provided with thethird RF filter 67 (corresponding to the second RF filter in the presentdisclosure) for protecting the pulsed power supply 65. The third RFfilter 67 is provided in the matching device 53. Further, the pulsedpower supply 65 is coupled to the lower electrode 12 in a path 68between the lower electrode 12 and the pulsed power supply 65. The path68 is provided with a fourth RF filter 69 (corresponding to the first RFfilter in the present disclosure) for protecting the pulsed power supply65. The fourth RF filter 69 is provided in the matching device 53.Alternatively, a matching circuit may be provided in place of the thirdRF filter 67 and the fourth RF filter 69, or the third RF filter 67, thefourth RF filter 69, and the matching circuit may be provided together.

In one example, the third RF filter 67 is configured to be variable inimpedance. That is, the third RF filter 67 includes at least onevariable passive component and has variable impedance. The variablepassive component may be either coil (inductor) or condenser(capacitor), for example. In addition, the same function can be achievedwith any variable impedance element such as a diode, not limited to acoil or a condenser. The number and position of the variable passivecomponent can also be appropriately designed by those skilled in theart. Furthermore, the element itself does not have to be variable. Forexample, a plurality of elements with fixed impedance values may beprovided, and a switching circuit may be used to switch the combinationof the elements with fixed impedance values to vary the impedance. Acircuit configuration including the third RF filter 67 and a circuitconfiguration including the fourth RF filter 69 can be appropriatelydesigned by those skilled in the art.

In this case, the tilt angle is controlled by adjusting the pulse-shapedvoltage from the pulsed power supply 65. For example, if thepulse-shaped voltage from the pulsed power supply 65 increases, the tiltcorrection angle may be increased. The tilt angle control by thepulse-shaped DC voltage from the pulsed power supply 65 is the same asthe tilt angle control by the DC voltage from the DC power supply 60described above.

In addition, when the pulsed power supply 65 includes a DC power supplyand a pulse generator and functions as a power supply for plasmageneration, the first matching circuit 54 may be omitted. In this case,the pulsed power supply 65 may function as a power supply for generatingplasma alone.

Further, as shown in FIG. 21A, an example of this configuration may be aconfiguration in which a first pulsed power supply 90 and a secondpulsed power supply 91 are arranged in the configuration shown in FIG.2A. Each of the first pulsed power supply 90 and the second pulsed powersupply 91 may be configured such that the power supply itself applies apulsed voltage and to include a DC power supply and a device (pulsegenerator) downstream of the DC power supply to pulse voltage.

The first pulsed power supply 90 is provided in place of the first highfrequency power supply 50, and applies a pulse-shaped negative first DCvoltage (hereinafter referred to as “first pulse voltage”) to the lowerelectrode 12 as source power for plasma generation. The first pulsevoltage may be at a first frequency in the range of 27 MHz to 100 MHz,and in one example is 40 MHz. The first pulsed power supply 90 iscoupled to the lower electrode 12 via a path 92. The path 92 is providedwith a fifth RF filter 93 for protecting the first pulsed power supply90. The first high frequency power supply 50 may not be electricallycoupled to the lower electrode 12, and may be coupled to the shower head20, which is the upper electrode.

The second pulsed power supply 91 is provided in place of the secondhigh frequency power supply 51 and the third high frequency power supply52, and applies a pulse-shaped negative second DC voltage (hereinafterreferred to as “second pulse voltage”) to the lower electrode 12 as biaspower for attracting ions into the wafer W. The second pulse voltage maybe at a second frequency in the range of 100 kHz to 15 MHz, and in oneexample is 400 kHz. The second pulsed power supply 91 is coupled to thelower electrode 12 via the path 92. The path 92 is provided with a sixthRF filter 94 (corresponding to the fourth RF filter in the presentdisclosure) for protecting the second pulsed power supply 91.

The second pulsed power supply 91 is provided in place of the DC powersupply 60 and applies a negative DC voltage to the edge ring 14. Thesecond pulsed power supply 91 is coupled to the edge ring 14 via a path95. The path 95 is provided with a variable passive component 96 and aseventh RF filter 97 (corresponding to the fifth RF filter in thepresent disclosure) for protecting the second pulsed power supply 91.The variable passive component 96 and the seventh RF filter 97 arearranged in this order from the edge ring 14 side.

In one example, the variable passive component 96 is configured to bevariable in impedance. The variable passive component 96 may be eithercoil (inductor) or condenser (capacitor), for example. In addition, thesame function can be achieved with any variable impedance element suchas a diode, not limited to a coil or a condenser. The number andposition of the variable passive component 96 can also be appropriatelydesigned by those skilled in the art. Furthermore, the element itselfdoes not have to be variable. For example, a plurality of elements withfixed impedance values may be provided, and a switching circuit may beused to switch the combination of the elements with fixed impedancevalues to vary the impedance. A circuit configuration including thevariable passive component 96 can be appropriately designed by thoseskilled in the art.

The bypass circuit 70 may be connected between the path 92 between thefirst pulsed power supply 90 and the second pulsed power supply 91 andthe lower electrode 12 and the path 95 between the second pulsed powersupply 91 and the edge ring 14.

In such a case, the pulse voltage from the second pulsed power supply 91is adjusted to control the tilt angle. For example, if the pulse voltagefrom the second pulsed power supply 91 is increased, the tilt correctionangle can be increased. The tilt angle control by the pulsed DC voltagefrom the second pulsed power supply 91 is the same as the tilt anglecontrol by the DC voltage from the DC power supply 60 described above.

The second pulsed power supply 91 may not be connected to the edge ring14 as shown in FIG. 21B. In such case, the bypass circuit 70 isconnected to the path 95 which is connected to the edge ring 14.

Other Embodiment

As described above, the frequency of the second high frequency power(bias RF power) LF1 supplied from the second high frequency power supply51 is 400 kHz to 13.56 MHz, but 5 MHz or less is more preferable. In thecase of performing etching, when high-aspect-ratio etching is performedon the wafer W, high ion energy is required to realize a vertical shapeof the pattern after etching. Therefore, according to results of studiesby the present inventors, it was found that, by setting the frequency ofthe second high frequency power LF1 to 5 MHz or less, the followabilityof ions to changes in the high frequency electric field was improved sothat the controllability of ion energy was improved.

Meanwhile, when the frequency of the second high frequency power LF1 isset to a low frequency of 5 MHz or less, the effect of varying theimpedance of the second RF filter 63 may be reduced. That is, thecontrollability of the tilt angle by adjustment of the impedance of thesecond RF filter 63 may be degraded. For example, in FIGS. 2A and 2B,when the electrical connection between the edge ring 14 and the secondRF filter 63 is non-contact or capacitive coupling, the tilt anglecannot be properly controlled even if the impedance of the second RFfilter 63 is adjusted. Therefore, in the present embodiment, the edgering 14 and the second RF filter 63 are electrically directly connectedto each other.

The edge ring 14 and the second RF filter 63 are electrically directlyconnected via a connecting portion. The edge ring 14 and the connectingportion are in contact, so that a direct current is conducted throughthe connecting portion. Hereinafter, an example of a structure of theconnecting portion (hereinafter, may be referred to as “contactstructure”) is described.

As illustrated in FIG. 22 , the connecting portion 200 has a conductivestructure 201 and a conductive member 202. The conductive structure 201connects the edge ring 14 and the second RF filter 63 via the conductivemember 202. Specifically, the conductive structure 201 has one endconnected to the second RF filter 63 and the other end exposed from theupper surface of the lower electrode 12, and is in contact with theconductive member 202.

The conductive member 202 is provided, for example, in a space formedbetween the lower electrode 12 and the edge ring 14 on the side of theelectrostatic chuck 13. The conductive member 202 contacts each of theconductive structure 201 and the lower surface of the edge ring 14. Inaddition, the conductive member 202 includes conductors, such as ametal, for example. Although the configuration of the conductive member202 is not particularly limited, each example is illustrated in FIGS.23A to 23F. FIGS. 23A to 23C are examples in which an elastic body isused as the conductive member 202.

As illustrated in FIG. 23A, for the conductive member 202, a platespring biased in the vertical direction may be used. As illustrated inFIG. 23B, for the conductive member 202, a coil spring elongated in ahorizontal direction, while being wound in a screw shape, may be used.As illustrated in FIG. 23C, for the conductive member 202, a springelongated in a vertical direction, while being wound in a screw shape,may be used. Also, these conductive members 202 are elastic bodies, andelastic force acts in the vertical direction. By this elastic force, theconductive member 202 is brought into close contact with the conductivestructure 201 and a lower surface of the edge ring 14 with a desiredcontact pressure, so that the conductive structure 201 and the edge ring14 are electrically connected to each other.

As illustrated in FIG. 23D, a pin that is lifted and lowered by alifting mechanism (not shown) may be used for the conductive member 202.In this case, when the conductive member 202 is lifted, the conductivemember 202 is brought into close contact with each of the conductivestructure 201 and the lower surface of the edge ring 14. Then, byadjusting the pressure applied when the conductive member 202 is liftedand lowered, the conductive member 202 is brought into close contactwith each of the conductive structure 201 and the lower surface of theedge ring 14 with a desired contact pressure.

As illustrated in FIG. 23E, a wire connecting the conductive structure201 and the edge ring 14 may be used for the conductive member 202. Oneend of the wire is joined to the conductive structure 201, and the otherend is joined to the lower surface of the edge ring 14. The joining ofthe wire may be in ohmic contact with the conductive structure 201 orthe lower surface of the edge ring 14, and, for example, the wire iswelded or pressed. And, when a wire is used for the conductive member202 as described above, the conductive member 202 is in contact witheach of the conductive structure 201 and the lower surface of the edgering 14, and the conductive structure 201 and the edge ring 14 areelectrically connected to each other.

As described above, even when any of the conductive members 202illustrated in FIGS. 23A to 23E are used, as illustrated in FIG. 22 ,the edge ring 14 and the second RF filter 63 may be electricallydirectly connected via the connecting portion 200. Therefore, thefrequency of the second high frequency power LF1 may be set to a lowfrequency of 5 MHz or less, so that the controllability of the ionenergy may be improved.

In addition, when the tilt angle is controlled by adjusting the drivingamount of the lifting device 80, the driving amount to be adjusted maybe suppressed to be small because the connecting portion 200 isprovided. As a result, it is possible to suppress the occurrence ofdischarge between the wafer W and the edge ring 14. In addition, asdescribed above, by adjusting the driving amount of the lifting device80 and the impedance of the second RF filter 63, the adjustment range ofthe tilt angle may be widened and the tilt angle may be controlled to adesired value.

In addition, in the above embodiment, as the conductive member 202, theleaf spring illustrated in FIG. 23A, the coil spring illustrated in FIG.23B, the spring illustrated in FIG. 23C, the pin illustrated in FIG.23D, and the wire illustrated in FIG. 23E are illustrated, but these maybe used in combination.

In addition, in the connecting portion 200 of the above embodiment, asillustrated in FIG. 23F, a conductor film 203 may be provided betweenthe conductive member 202 of the connecting portion 200 and the edgering 14. For the conductor film 203, for example, a metal film is used.The conductor film 203 is provided in at least at a portion in contactwith the conductive member 202 on the lower surface of the edge ring 14.The conductor film 203 may be provided on the entire lower surface ofthe edge ring 14, or a plurality of conductor films 203 may be providedin a substantially annular shape as a whole. In either case, theresistance due to the contact of the conductive member 202 may besuppressed by the conductor film 203, so that the edge ring 14 and thesecond RF filter 63 may be connected appropriately.

It is preferable that the connecting portion 200 of the above embodimenthas a configuration in which the conductive member 202 is protected fromplasma, when the edge ring 14 is lifted by the lifting device 80. FIG.24A to 24G each illustrate an example of the plasma countermeasure ofthe conductive member 202.

As illustrated in FIG. 24A, on the lower surface of the edge ring 14,protrusions 14 a and 14 b protruding downward from the lower surface maybe provided. In the illustrated example, the protrusion 14 a is providedon the radially inner side of the conductive member 202, and theprotrusion 14 b is provided on the radially outer side of the conductivemember 202. That is, the conductive member 202 is provided in a concaveportion formed by the protrusions 14 a and 14 b. In this case, theprotrusions 14 a and 14 b may suppress the plasma from rounding to theconductive member 202, so that the conductive member 202 may beprotected.

In addition, in the example of FIG. 24A, although the protrusions 14 aand 14 b are provided on the lower surface of the edge ring 14, theshape which suppresses the rounding of plasma is not limited thereto andmay be determined according to the etching apparatus 1. In addition, theshape of the edge ring 14 may be determined so that the edge ring 14 maybe lifted and lowered appropriately by the lifting device 80.

As illustrated in FIG. 24B, an insulating member 210 may be providedinside the conductive member 202 on the upper surface of the lowerelectrode 12. The insulating member 210 is provided separately from thelower electrode 12 and has, for example, an annular shape. In this case,the insulating member 210 may suppress the plasma from rounding to theconductive member 202, thereby protecting the conductive member 202.

As illustrated in FIG. 24C, the protrusion 14 a of the edge ring 14illustrated in FIG. 24A and the insulating member 210 illustrated inFIG. 24B may be provided on both sides. In this case, by the protrusion14 a and the insulating member 210, the plasma may be further suppressedfrom rounding, thereby protecting the conductive member 202.

As illustrated in FIG. 24D, the protrusions 14 a and 14 b of the edgering 14 illustrated in FIG. 24A and the insulating member 210illustrated in FIG. 24B may be provided on both sides. The conductivemember 202 is in contact with the protrusion 14 b. In addition, theinsulating member 210 is provided between the protrusions 14 a and 14 b.In this case, a labyrinth structure is formed by the protrusions 14 aand 14 b and the insulating member 210, and the rounding of plasma maybe further suppressed, thereby protecting the conductive member 202.

As illustrated in FIG. 24E, the edge ring 14 may be divided into anupper edge ring 140 and a lower edge ring 141. The upper edge ring 140is configured to be liftable by the lifting device 80. The lower edgering 141 is not lifted. The conductive member 202 is provided in contactwith the lower surface of the upper edge ring 140 and the upper surfaceof the lower edge ring 141. The conductive structure 201 is connected tothe lower edge ring 141. In this case, the upper edge ring 140 and thesecond RF filter 63 are electrically directly connected via theconductive member 202, the lower edge ring 141, and the conductivestructure 201.

A protrusion 140 a protruding downward from the lower surface isprovided on the outermost periphery of the lower surface of the upperedge ring 140. A protrusion 141 a protruding upward from the uppersurface is provided on the innermost periphery of the upper surface ofthe lower edge ring 141. In this case, the protrusions 140 a and 141 amay suppress the plasma from rounding to the conductive member 202,thereby protecting the conductive member 202.

FIG. 24F is a modification of FIG. 24E. In the example illustrated inFIG. 24E, the conductive structure 201 is connected to the lower edgering 141, but in the example illustrated in FIG. 24F, one end of theconductive structure 201 is exposed from the upper surface of the lowerelectrode 12 and is in contact with the conductive member 220. Theconductive member 220 is provided in a space formed between the lowersurface of the lower edge ring 141 and the upper surface of the lowerelectrode 12 radially outside the electrostatic chuck 13. That is, theconductive member 220 contacts the lower surface of the lower edge ring141 and the conductive structure 201. In this case, the upper edge ring140 and the second RF filter 63 are electrically directly connected viathe conductive member 202, the lower edge ring 141, the conductivemember 220, and the conductive structure 201. Also, in this example, theprotrusions 140 a and 141 a may prevent the plasma from rounding to theconductive member 202, thereby protecting the conductive member 202.

FIG. 24G is a modification of FIG. 24E. In the example illustrated inFIG. 24E, the conductive member 202 is provided on the upper surface ofthe lower edge ring 141, but in the example illustrated in FIG. 24G, theconductive member 202 is provided on the upper surface of the lowerelectrode 12. The conductive member 202 contacts the lower surface ofthe upper edge ring 140 and the conductive structure 201. One end of theconductive structure 201 is exposed from the upper surface of theelectrostatic chuck 13 and contacts the conductive member 202. In thiscase, the upper edge ring 140 and the second RF filter 63 areelectrically directly connected via the conductive member 202 and theconductive structure 201. Also in this example, the protrusions 140 aand 141 a prevent the plasma from rounding to the conductive member 202,and thus, the conductive member 202 may be protected.

Moreover, in the above embodiment, a combination of the configurationsillustrated in FIGS. 24A to 24G may also be used. Moreover, in theconnecting portion 200, plasma-resistant coating may be performed on aportion other than a portion in contact with the edge ring 14 of thesurface of the conductive member 202. In this case, the conductivemember 202 may be protected from plasma.

Next, a planar arrangement of the conductive member 202 is described.FIGS. 25A to 25C each illustrate an example of a planar arrangement ofthe conductive member 202. As illustrated in FIGS. 25A and 25B, theconnecting portion 200 may include a plurality of conductive members202, and the plurality of conductive members 202 may be providedconcentrically with the edge ring 14 at equal intervals. In the exampleof FIG. 25A, the conductive member 202 is provided in eight locations,and in FIG. 25B, the conductive member 202 is provided in 24 locations.Moreover, as illustrated in FIG. 25C, the conductive member 202 may beprovided on concentric circles with the edge ring 14 in an annularshape.

From the viewpoint of uniformly performing etching and uniformizing theshape of the sheath (from the viewpoint of process uniformity), asillustrated in FIG. 25C, it is preferable to form the conductive member202 in an annular shape with respect to the edge ring 14 and to make theconductive member 202 contact the ring 14 uniformly on thecircumference. Similarly, from the viewpoint of process uniformity, asillustrated in FIGS. 25A and 25B, even in the case of providing aplurality of conductive members 202, it is preferable to arrange theplurality of conductive members 202 at equal intervals in acircumferential direction and provide a contact point with respect tothe edge ring 14 in point symmetry. In addition, it is better toincrease the number of conductive members 202 as in the example of FIG.25B as compared to the example of FIG. 25A and make them closer to theannular shape as illustrated in FIG. 25C. In addition, although thenumber of the conductive members 202 is not particularly limited, inorder to ensure symmetry, three or more conductive members arepreferable, and 3 to 36 conductive members may be provided, for example.

However, in terms of the device configuration, in order to avoidinterference with other members, it may be difficult to make theconductive member 202 to have an annular shape or to increase the numberof the conductive members 202 in some cases. Therefore, the planararrangement of the conductive member 202 may be appropriately set inconsideration of the conditions for process uniformity, the constraintconditions on the device configuration, and the like.

Next, a relationship between the connecting portion 200 and the first RFfilter 62 and the second RF filter 63 is described. FIGS. 26A to 26Ceach schematically illustrates an example of the configuration of theconnecting portion 200, the first RF filter 62, and the second RF filter63.

As illustrated in FIG. 26A, for example, when one first RF filter 62 andone second RF filter 63 are provided for each of the eight conductivemembers 202, the connecting portion 200 may have a relay member 230additionally. In addition, although FIG. 26A illustrates a case in whichthe relay member 230 is provided in the connecting portion 200illustrated in FIG. 25A, the relay member 230 may also be provided inthe connecting portion 200 illustrated in either FIG. 25B or 25C. Inaddition, the relay member 230 may be provided in plurality.

The relay member 230 is annularly provided on a concentric circle withthe edge ring 14 in the conductive structure 201 between the conductivemember 202 and the second RF filter 63. The relay member 230 isconnected to the conductive member 202 by the conductive structure 201a. That is, eight conductive structures 201 a elongate radially from therelay member 230 in plan view, and are connected to the eight conductivemembers 202, respectively. Further, the relay member 230 is connected tothe second RF filter 63 via the first RF filter 62 in the conductivestructure 201 b.

In this case, for example, even when the second RF filter 63 is notdisposed at the center of the edge ring 14, the electricalcharacteristics (arbitrary voltage and current values) of the relaymember 230 may be uniformly executed on the circumference, and it ispossible to make the electrical characteristics for each of the eightconductive members 202 uniform. As a result, etching may be performeduniformly and the shape of the sheath may be uniform.

As illustrated in FIG. 26B, for example, with respect to the eightconductive members 202, a plurality of first RF filters 62, for example,eight RF filters 62, are provided, and one second RF filter 63 may beprovided. Thus, with respect to the number of the conductive members202, the number of the first RF filters 62 may be set appropriately. Inaddition, also in the example of FIG. 26B, the relay member 230 may beprovided.

As illustrated in FIG. 26C, for example, a plurality of first RF filters62, for example, eight first RF filters 62, may be provided for eightconductive members 202, and a plurality of second RF filters 63, forexample, eight second RF filters 63, may be provided. As describedabove, with respect to the number of the conductive members 202, thenumber of the second RF filters 63 with variable impedance may beappropriately set. Also in the example of FIG. 26C, the relay member 230may also be provided.

In addition, by providing a plurality of the second RF filters 63 havingvariable impedances, it is possible to individually and independentlycontrol the electrical characteristics of the plurality of conductivemembers 202. As a result, the electrical characteristics of each of theplurality of conductive members 202 may be controlled to be uniform, sothat the uniformity of the process may be improved.

Next, as a contact structure for the edge ring 14, examples other thanthe examples illustrated in FIGS. 22 and 23A to 23F is described. FIGS.27A to 27D and 28A to 28D each illustrate another example of theconfiguration of the connecting portion.

FIGS. 27A to 27D are examples in which a lifting pin 300 of the liftingdevice 80 are formed of an insulator and a connecting portion 310 isprovided inside the lifting pin 300.

As illustrated in FIG. 27A, the lifting device 80 may include thelifting pin 300 in place of the lifting pin 81 in the above embodiment.The lifting pin 300 elongates in a vertical direction from the lowersurface of the edge ring 14, and is provided through the electrostaticchuck 13, the lower electrode 12, the support member 17, and the bottomof the chamber 10. A portion between the lifting pin 300 and the chamber10 is sealed in order to hermetically close the inside of the chamber10. The lifting pin 300 is formed of an insulator. In addition, thelifting pin 300 is configured to be liftable by the driving source 82provided outside the chamber 10.

The connecting portion 310 is provided inside the lifting pin 300. Theconnecting portion 310 directly connects the edge ring 14 and thelifting pin 300, and connects the edge ring 14 and the second RF filter63. Specifically, the connecting portion 310 has one end connected tothe second RF filter 63 and the other end exposed from the upper surfaceof the lifting pin 300, and is in contact with the lower surface of theedge ring 14.

As illustrated in FIGS. 27B and 27C, the connecting portion 310 providedinside the lifting pin 300 may have a conductive structure 311 and aconductive member 312. The conductive structure 311 connects the edgering 14 and the second RF filter 63 via the conductive member 312.Specifically, the conductive structure 311 has one end connected to thesecond RF filter 63 and the other end exposed in the upper space insidethe lifting pin 300, and is in contact with the conductive member 312.

The conductive member 312 is provided in the upper space inside thelifting pin 300. A conductive member 312 contacts each of the conductivestructure 311 and the lower surface of the edge ring 14. In addition,the conductive member 312 is formed of a conductor, such as a metal, forexample. The configuration of the conductive member 312 is notparticularly limited, but, for example, as illustrated in FIG. 27B, aleaf spring having elasticity applied in the vertical direction may beused, and as illustrated in FIG. 27C, a wire connecting the conductivestructure and the edge ring 14 may be used. Alternatively, for theconductive member 312, a coil spring illustrated in FIG. 23B, a springillustrated in FIG. 23C, a pin illustrated in FIG. 23D, or the like maybe used. In this case, the upper edge ring 140 and the second RF filter63 are electrically directly connected via the conductive member 312 andthe conductive structure 311.

As illustrated in FIG. 27D, the lifting pin 300 has a hollow cylindricalshape with upper and lower surfaces open, and the connecting portion 310provided inside the lifting pin 300 may have another conductivestructure (second conductive structure) 313 in addition to theconductive structure (first conductive structure) 311 and the conductivemember 312. The conductive structure 313 is provided on the innersurface of the lifting pin 300. The conductive structure 313 may be, forexample, a metal film or a metal cylinder.

The conductive structure 311 is connected to a lower end of theconductive structure 313. The conductive member 312 is connected to anupper end of the conductive structure 313. In this case, the upper edgering 140 and the second RF filter 63 are electrically directly connectedvia the conductive member 312, the conductive structure 313, and theconductive structure 311.

As mentioned above, no matter which connecting portion 310 illustratedin FIGS. 27A to 27D is used, the edge ring 14 and the second RF filter63 may be electrically directly connected via the connecting portion310. Therefore, the frequency of the second high frequency power LF1 maybe set to a low frequency of 5 MHz or less, so that the controllabilityof the ion energy may be improved.

In addition, since the connecting portion 310 of the above embodiment isprovided inside the lifting pin 300 formed of an insulator, it is notnecessary to have a configuration protected from plasma.

FIGS. 28A to 28D illustrate examples in which a lifting pin 400 of alifting device 80 is formed of a conductor and the lifting pin 400itself constitute a connecting portion.

As illustrated in FIG. 28A, the lifting device 80 may include thelifting pin 400 in place of the lifting pins 81 and 300 of the aboveembodiment. The lifting pin 400 elongates in a vertical direction fromthe lower surface of the edge ring 14 and is provided through theelectrostatic chuck 13, the lower electrode 12, the support member 17,and the bottom of the chamber 10. A portion between the lifting pin 400and the chamber 10 is sealed in order to hermetically close the insideof the chamber 10. The lifting pin 400 is formed of a conductor. Inaddition, the lifting pin 400 is configured to be liftable by thedriving source 82 provided outside the chamber 10.

A conductive structure 410 is connected to a lower end of the liftingpin 400. The conductive structure 410 is connected to a second RF filter63. In this case, the upper edge ring 140 and the second RF filter 63are electrically directly connected via the lifting pin 400 and theconductive structure 410.

The lifting pin 400 preferably has a configuration that is protectedfrom plasma when the edge ring 14 is lifted by the lifting device 80.FIGS. 28B to 28C each illustrate an example of the plasma countermeasureof the lifting pins 400.

As illustrated in FIG. 28B, the insulating member 210 illustrated inFIG. 24B may be provided inside the lifting pin 400 on the upper surfaceof the lower electrode 12. In this case, the insulating member 210 maysuppress the plasma from rounding to the lifting pin 400, therebyprotecting the lifting pin 400. In addition, the configuration forsuppressing the rounding of plasma is not limited thereto, and any oneof the configurations of FIGS. 24A and 24C to 24G may be applied.

As illustrated in FIG. 28C, an insulating member 401 having plasmaresistance may be provided on the outer surface of the lifting pin 400.The insulating member 401 may be, for example, a film of an insulator ora cylinder formed of an insulator. In this case, the lifting pin 400 maybe protected from plasma by the insulating member 401. Moreover, in theconfiguration of FIG. 28B, the insulating member 401 illustrated in FIG.28C may be further provided.

As described above, even in the case illustrated in FIGS. 28A to 28C,the edge ring 14 and the second RF filter 63 may be electricallydirectly connected via the lifting pin 400. Therefore, the frequency ofthe second high frequency power LF1 may be set to a low frequency of 5MHz or less, so that the controllability of the ion energy may beimproved.

Also, in FIGS. 28A to 28C, the lifting pin 400 itself constitutes theconnecting portion, but as illustrated in FIG. 28D, the connectingportion 420 may be additionally provided inside the lifting pin 400. Theconnecting portion 420 may have a conductive structure 421 and aconductive member 422. The conductive structure 421 connects the edgering 14 and the second RF filter 63 via the conductive member 422.Specifically, one end of the conductive structure 421 is connected tothe second RF filter 63, and the other end thereof is exposed in theupper space of the lifting pin 400 and contacts the conductive member422. Also, the conductive structure 410 is included in the conductivestructure 421.

The conductive member 422 is provided in the upper space inside thelifting pin 400. The conductive member 422 contacts each of theconductive structure 421 and the lower surface of the edge ring 14. Inaddition, the conductive member 422 is formed of a conductor, such as ametal, for example. Although the configuration of the conductive member312 is not particularly limited, for example, a plate spring biased in avertical direction illustrated in FIG. 23A may be used. Alternatively,the coil spring illustrated in FIG. 23B, the spring illustrated in FIG.23C, the pin illustrated in FIG. 23D, the wire illustrated in FIG. 23E,or the like may be used. In this case, the upper edge ring 140 and thesecond RF filter 63 are electrically directly connected via theconductive member 312 and the conductive structure 311 in addition tothe lifting pin 400. Moreover, since the resistance due to the contactof the lifting pin 400 and the conductive member 312 may be suppressed,the edge ring 14 and the second RF filter 63 may be connected moreappropriately.

Other Embodiment

Although the etching apparatus 1 of the above embodiment is acapacitively coupled etching apparatus, the etching apparatus to whichthe present disclosure is applied is not limited thereto. For example,the etching apparatus may be an inductively coupled etching apparatus.

It should be considered that embodiment disclosed herein is illustrativein every point, and is not restrictive. The above embodiments may beomitted, replaced, or changed in various forms without departing fromthe appended claims and the gist thereof.

Embodiments of the present disclosure further include the followingaspects.

(Additional Statement A1)

An etching apparatus performing etching on a substrate, the etchingapparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a radio frequency (RF) filter connected to the edge ring and changingimpedance; and

a bypass circuit connected to the matching circuit or a path between thematching circuit and the electrode and connected to the RF filter or apath between the RF filter and the edge ring.

(Additional Statement A2)

The etching apparatus of additional statement A1, further comprising:

a DC power supply applying a negative polarity DC voltage to the edgering via the RF filter,

wherein the bypass circuit is connected to the matching circuit or apath between the matching circuit and the electrode and connected to theDC power supply or to a path between the DC power supply and the edgering.

(Additional Statement A3)

An etching apparatus performing etching on a substrate, the etchingapparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a DC power supply applying a negative DC voltage to the edge ring; and

a bypass circuit connected to the matching circuit or a path between thematching circuit and the electrode and connected to the DC power supplyor a path between the DC power supply and the edge ring.

(Additional Statement A4)

The etching apparatus of any one of additional statements A1 to A3,further comprising:

a lifting device lifting and lowering the edge ring.

(Additional Statement A5)

An etching apparatus performing etching on a substrate, the etchingapparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a lifting device lifting and lowering the edge ring; and

a bypass circuit connected to the matching circuit, a path between thematching circuit and the electrode, and the edge ring.

(Additional Statement A6)

The etching apparatus of any one of additional statements A1 to A5,wherein

the bypass circuit controls an amount of power supplied to the edge ringand adjusts an initial tilt angle in an edge region of the substratemounted on the electrostatic chuck.

(Additional Statement A7)

The etching apparatus of any one of additional statements A1 to A6,wherein

high frequency powers of a plurality of frequencies are supplied fromthe high frequency power supply, and

a tilt angle in an edge region of the substrate mounted on theelectrostatic chuck is controlled for high frequency powers of two ormore frequencies, among the high frequency powers of the plurality offrequencies.

(Additional Statement A8)

The etching apparatus of additional statement A7, wherein

the bypass circuit is provided in plurality.

(Additional Statement A9)

A method for performing etching on a substrate using an etchingapparatus, wherein the etching apparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a radio frequency (RF) filter connected to the edge ring and changingimpedance; and

a bypass circuit connected to the matching circuit or a path between thematching circuit and the electrode and connected to the RF filter or apath between the RF filter and the edge ring,

wherein the method includes a process of adjusting an initial tilt anglebefore etching in an edge region of the substrate mounted on theelectrostatic chuck by controlling an amount of power supplied to theedge ring by the bypass circuit.

(Additional Statement A10)

A method for performing etching on a substrate using an etchingapparatus, wherein the etching apparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a DC power supply applying a negative polarity DC voltage to the edgering; and

a bypass circuit connected to the matching circuit or a path between thematching circuit and the electrode and connected to the DC power supplyor a path between the DC power supply and the edge ring,

wherein the method includes a process of adjusting an initial tilt anglebefore etching in an edge region of the substrate mounted on theelectrostatic chuck by controlling an amount of power supplied to theedge ring by the bypass circuit.

(Additional Statement A11)

A method for performing etching on a substrate using an etchingapparatus, wherein the etching apparatus comprising:

a chamber;

a substrate support provided inside the chamber and including anelectrode, an electrostatic chuck, and a conductive edge ring disposedto surround the substrate mounted on the electrostatic chuck;

a high frequency power supply supplying high frequency power to theelectrode;

at least one matching circuit connected to the high frequency powersupply;

a lifting device lifting and lowering the edge ring; and

a bypass circuit connected to the matching circuit, a path between thematching circuit and the electrode, and the edge ring,

wherein the method includes a process of adjusting an initial tilt anglebefore etching in an edge region of the substrate mounted on theelectrostatic chuck by controlling an amount of power supplied to theedge ring by the bypass circuit.

(Additional Statement B1)

A plasma processing apparatus comprising:

a chamber;

a substrate support disposed in the chamber and including a lowerelectrode, a substrate supporting surface for supporting a substrate,and an edge ring disposed to surround the substrate placed on thesubstrate supporting surface;

an upper electrode disposed above the lower electrode;

a power supply configured to supply two or more powers having differentfrequencies, the power supply including a source power supply configuredto supply a source power for generating plasma from a gas in the chamberto the upper electrode or the lower electrode, and at least one biaspower supply configured to supply one bias power or two or more biaspowers having different frequencies to the lower electrode;

at least one variable passive component electrically connected to theedge ring; and

at least one bypass circuit that electrically connects the power supplyand the edge ring and is configured to supply a part of at least onepower selected from the group consisting of the source power and atleast one bias power to the edge ring.

(Additional Statement B2)

The plasma processing apparatus of additional statement B1, wherein saidat least one bypass circuit is configured to supply a part of said atleast one power selected depending on a frequency to the edge ring.

(Additional Statement B3)

The plasma processing apparatus of additional statement B2, wherein saidat least one bypass circuit is configured to include a combination of abypass circuit independently provided for each frequency and a bypasscircuit commonly provided for a plurality of frequencies.

(Additional Statement B4)

The plasma processing apparatus of any one of additional statements B1to B3, wherein said at least one bypass circuit is configured to controla magnitude of said at least one power supplied to the edge ring.

(Additional Statement B5)

The plasma processing apparatus of any one of additional statements B1to B4, wherein the source power supply is configured to supply a sourceRF power as the source power, and

said at least one bias power supply is configured to apply, as the biaspower, at least one bias RF power having different frequencies or atleast one negative pulse voltage having different frequencies.

(Additional Statement B6)

The plasma processing apparatus of additional statement B5, furthercomprising:

a matching device including a first matching circuit and at least onesecond matching circuit,

wherein said at least one bias power supply is configured to supply, asthe bias power, at least one bias RF power having different frequencies,

the source power supply is connected to the upper electrode or the lowerelectrode through the first matching circuit, and

said at least one bias power supply is connected to the lower electrodethrough said at least one second matching circuit.

(Additional Statement B7)

The plasma processing apparatus of additional statement B6, wherein thebypass circuit is disposed on a first path that connects

the matching device or a path between the matching device and the upperelectrode or the lower electrode and

the variable passive component or a path between the variable passivecomponent and the edge ring.

(Additional Statement B8)

The plasma processing apparatus of additional statement B5, wherein saidat least one bias power supply is configured to apply, as the biaspower, at least one negative pulse voltage having different frequencies,and

said at least one bias power supply is connected to the lower electrodethrough at least one first RF filter.

(Additional Statement B9)

The plasma processing apparatus of additional statement B8, wherein saidat least one bias power supply is connected to the edge ring through asecond RF filter.

(Additional Statement B10)

The plasma processing apparatus of additional statement B9, wherein thebypass circuit is disposed on a second path that connects

the matching device or a path between the matching device and the upperelectrode or the lower electrode and

the second RF filter or a path between the second RF filter and the edgering.

(Additional Statement B11)

The plasma processing apparatus of additional statement B10, wherein thesecond RF filter includes said at least one variable passive component.

(Additional Statement B12)

The plasma processing apparatus of any one of additional statements B1to B4, wherein the power supply further includes a DC power supplyconfigured to apply a negative DC voltage to the edge ring, the DC powersupply being connected to the edge ring through at least one third RFfilter.

(Additional Statement B13)

The plasma processing apparatus of additional statement B12, wherein thebypass circuit is disposed on a third path that connects

the matching device or a path between the matching device and the upperelectrode or the lower electrode and

the DC power supply or a path between the DC power supply and the edgering.

(Additional Statement B14)

The plasma processing apparatus of additional statement B13, whereinsaid third RF filter includes said at least one variable passivecomponent.

(Additional Statement B15)

The plasma processing apparatus of any one of additional statements B12to B14, further comprising:

a lifting device configured to lift and lower the edge ring.

(Additional Statement B16)

The plasma processing apparatus of any one of additional statements B1to B4, wherein the source power supply is configured to apply a negativefirst pulse voltage as the source power,

said at least one bias power supply is configured to apply at least onenegative second pulse voltage as the bias power, and

a frequency of the first pulse voltage and a frequency of the secondpulse voltage are different.

(Additional Statement B17)

The plasma processing apparatus of additional statement B16, whereinsaid at least one bias power supply is connected to the lower electrodethrough a fourth RF filter and connected to the edge ring through afifth RF filter, and

the bypass circuit is disposed on a fourth path that connects

the fourth RF filter or a path between the fourth RF filter and thelower electrode and

the fifth RF filter or a path between the fifth RF filter and the edgering.

(Additional Statement B18)

A plasma processing apparatus comprising:

a chamber;

a substrate support disposed in the chamber and including a lowerelectrode, a substrate supporting surface for supporting a substrate,and an edge ring disposed to surround the substrate placed on thesubstrate supporting surface;

an upper electrode disposed above the lower electrode;

a power supply configured to supply two or more powers having differentfrequencies, the power supply including a source power supply configuredto supply a source power for generating plasma from a gas in the chamberto the upper electrode or the lower electrode, and at least one biaspower supply configured to supply one bias power or two or more biaspowers having different frequencies to the lower electrode;

a lifting device configured to lift and lower the edge ring; and

at least one bypass circuit that electrically connects the power supplyand the edge ring and is configured to supply a part of at least onepower selected from the group consisting of the source power and atleast one bias power to the edge ring.

(Additional Statement B19)

The plasma processing apparatus of additional statement B18, wherein thebypass circuit is disposed on a fifth path that connects

the matching circuit or a path between the matching circuit and theupper electrode or the lower electrode and the edge ring.

(Additional Statement B20)

An etching method using a plasma processing apparatus, wherein theplasma processing apparatus includes:

a chamber;

a substrate support disposed in the chamber and including a lowerelectrode, a substrate supporting surface for supporting a substrate,and an edge ring disposed to surround the substrate placed on thesubstrate supporting surface;

an upper electrode disposed above the lower electrode;

a power supply configured to supply two or more powers having differentfrequencies, the power supply including a source power supply configuredto supply a source power for generating plasma from a gas in the chamberto the upper electrode or the lower electrode, and at least one biaspower supply configured to supply one bias power or two or more biaspowers having different frequencies to the lower electrode;

at least one variable passive component electrically connected to theedge ring; and

at least one bypass circuit that electrically connects the power supplyand the edge ring and is configured to supply a part of at least onepower selected from the group consisting of the source power and atleast one bias power to the edge ring,

the etching method comprising:

(a) placing a substrate on the substrate supporting surface;

(b) generating plasma from a gas in the chamber;

(c) etching the substrate using the generated plasma; and

(d) controlling the amount of power supplied to the edge ring using thebypass circuit to adjust an incidence angle of ions in the plasma withrespect to an edge region of the substrate.

1. A plasma processing apparatus comprising: a chamber; a substratesupport disposed in the chamber and including a lower electrode, asubstrate supporting surface for supporting a substrate, and an edgering disposed to surround the substrate placed on the substratesupporting surface; an upper electrode disposed above the lowerelectrode; a power supply configured to supply two or more powers havingdifferent frequencies, the power supply including a source power supplyconfigured to supply a source power for generating plasma from a gas inthe chamber to the upper electrode or the lower electrode, and at leastone bias power supply configured to supply one bias power or two or morebias powers having different frequencies to the lower electrode; atleast one variable passive component electrically connected to the edgering; and at least one bypass circuit that electrically connects thepower supply and the edge ring and is configured to supply a part of atleast one power selected from the group consisting of the source powerand at least one bias power to the edge ring.
 2. The plasma processingapparatus of claim 1, wherein said at least one bypass circuit isconfigured to supply a part of said at least one power selecteddepending on a frequency to the edge ring.
 3. The plasma processingapparatus of claim 2, wherein said at least one bypass circuit isconfigured to include a combination of a bypass circuit independentlyprovided for each frequency and a bypass circuit commonly provided for aplurality of frequencies.
 4. The plasma processing apparatus of claim 1,wherein said at least one bypass circuit is configured to control amagnitude of said at least one power supplied to the edge ring.
 5. Theplasma processing apparatus of claim 1, wherein the source power supplyis configured to supply a source RF power as the source power, and saidat least one bias power supply is configured to apply, as the biaspower, at least one bias RF power having different frequencies or atleast one negative pulse voltage having different frequencies.
 6. Theplasma processing apparatus of claim 5, further comprising: a matchingdevice including a first matching circuit and at least one secondmatching circuit, wherein said at least one bias power supply isconfigured to supply, as the bias power, at least one bias RF powerhaving different frequencies, the source power supply is connected tothe upper electrode or the lower electrode through the first matchingcircuit, and said at least one bias power supply is connected to thelower electrode through said at least one second matching circuit. 7.The plasma processing apparatus of claim 6, wherein the bypass circuitis disposed on a first path that connects the matching device or a pathbetween the matching device and the upper electrode or the lowerelectrode and the variable passive component or a path between thevariable passive component and the edge ring.
 8. The plasma processingapparatus of claim 5, wherein said at least one bias power supply isconfigured to apply, as the bias power, at least one negative pulsevoltage having different frequencies, and said at least one bias powersupply is connected to the lower electrode through at least one first RFfilter.
 9. The plasma processing apparatus of claim 8, wherein said atleast one bias power supply is connected to the edge ring through asecond RF filter.
 10. The plasma processing apparatus of claim 9,wherein the bypass circuit is disposed on a second path that connectsthe matching device or a path between the matching device and the upperelectrode or the lower electrode and the second RF filter or a pathbetween the second RF filter and the edge ring.
 11. The plasmaprocessing apparatus of claim 10, wherein the second RF filter includessaid at least one variable passive component.
 12. The plasma processingapparatus of claim 1, wherein the power supply further includes a DCpower supply configured to apply a negative DC voltage to the edge ring,the DC power supply being connected to the edge ring through at leastone third RF filter.
 13. The plasma processing apparatus of claim 12,wherein the bypass circuit is disposed on a third path that connects thematching device or a path between the matching device and the upperelectrode or the lower electrode and the DC power supply or a pathbetween the DC power supply and the edge ring.
 14. The plasma processingapparatus of claim 13, wherein said third RF filter includes said atleast one variable passive component.
 15. The plasma processingapparatus of claim 12, further comprising: a lifting device configuredto lift and lower the edge ring.
 16. The plasma processing apparatus ofclaim 1, wherein the source power supply is configured to apply anegative first pulse voltage as the source power, said at least one biaspower supply is configured to apply at least one negative second pulsevoltage as the bias power, and a frequency of the first pulse voltageand a frequency of the second pulse voltage are different.
 17. Theplasma processing apparatus of claim 16, wherein said at least one biaspower supply is connected to the lower electrode through a fourth RFfilter and connected to the edge ring through a fifth RF filter, and thebypass circuit is disposed on a fourth path that connects the fourth RFfilter or a path between the fourth RF filter and the lower electrodeand the fifth RF filter or a path between the fifth RF filter and theedge ring.
 18. A plasma processing apparatus comprising: a chamber; asubstrate support disposed in the chamber and including a lowerelectrode, a substrate supporting surface for supporting a substrate,and an edge ring disposed to surround the substrate placed on thesubstrate supporting surface; an upper electrode disposed above thelower electrode; a power supply configured to supply two or more powershaving different frequencies, the power supply including a source powersupply configured to supply a source power for generating plasma from agas in the chamber to the upper electrode or the lower electrode, and atleast one bias power supply configured to supply one bias power or twoor more bias powers having different frequencies to the lower electrode;a lifting device configured to lift and lower the edge ring; and atleast one bypass circuit that electrically connects the power supply andthe edge ring and is configured to supply a part of at least one powerselected from the group consisting of the source power and at least onebias power to the edge ring.
 19. The plasma processing apparatus ofclaim 18, wherein the bypass circuit is disposed on a fifth path thatconnects the matching circuit or a path between the matching circuit andthe upper electrode or the lower electrode and the edge ring.
 20. Anetching method using a plasma processing apparatus, wherein the plasmaprocessing apparatus includes: a chamber; a substrate support disposedin the chamber and including a lower electrode, a substrate supportingsurface for supporting a substrate, and an edge ring disposed tosurround the substrate placed on the substrate supporting surface; anupper electrode disposed above the lower electrode; a power supplyconfigured to supply two or more powers having different frequencies,the power supply including a source power supply configured to supply asource power for generating plasma from a gas in the chamber to theupper electrode or the lower electrode, and at least one bias powersupply configured to supply one bias power or two or more bias powershaving different frequencies to the lower electrode; at least onevariable passive component electrically connected to the edge ring; andat least one bypass circuit that electrically connects the power supplyand the edge ring and is configured to supply a part of at least onepower selected from the group consisting of the source power and atleast one bias power to the edge ring, the etching method comprising:(a) placing a substrate on the substrate supporting surface; (b)generating plasma from a gas in the chamber; (c) etching the substrateusing the generated plasma; and (d) controlling the amount of powersupplied to the edge ring using the bypass circuit to adjust anincidence angle of ions in the plasma with respect to an edge region ofthe substrate.